mirror of
https://github.com/MariaDB/server.git
synced 2025-02-22 13:23:07 +01:00
5001300bd4
We now allow multitable queries with order by and limit, such as: delete t1.*, t2.* from t1, t2 order by t1.id desc limit 3; To predict what rows will be deleted, run the equivalent select: select t1.*, t2.* from t1, t2 order by t1.id desc limit 3; Additionally, index hints are now supported with single table delete statements: delete from t2 use index(xid) order by (id) limit 2; This approach changes the multi_delete SELECT result interceptor to use a temporary table to collect row ids pertaining to the rows that will be deleted, rather than directly deleting rows from the target table(s). Row ids are collected during send_data, then read during send_eof to delete target rows. In the event that the temporary table created in memory is not big enough for all matching rows, it is converted to an aria table. Other changes: - Deleting from a sequence now affects zero rows instead of emitting an error Limitations: - The federated connector does not create implicit row ids, so we to use a key when conditionally deleting. See the change in federated_maybe_16324629.test
8870 lines
196 KiB
Text
8870 lines
196 KiB
Text
set @save_default_engine=@@default_storage_engine;
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#######################################
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# #
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# Engine InnoDB #
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# #
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#######################################
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set global innodb_stats_persistent=1;
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set default_storage_engine=InnoDB;
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create table t1 (c1 integer, c2 integer, c3 integer);
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insert into t1(c1,c2,c3)
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values (1,1,1),(1,2,2),(1,3,3),
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(2,1,4),(2,2,5),(2,3,6),
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(2,4,7),(2,5,8);
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insert into t1 select c1+10,c2,c3+10 from t1;
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insert into t1 select c1+20,c2+1,c3+20 from t1;
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analyze table t1 persistent for all;
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Table Op Msg_type Msg_text
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test.t1 analyze status Engine-independent statistics collected
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test.t1 analyze status OK
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create view v1 as select * from t1 where c2=2;
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#######################################
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# Test without any index #
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#######################################
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#
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# Delete with value from subquery on the same table
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#
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analyze table t1 persistent for all;
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Table Op Msg_type Msg_text
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test.t1 analyze status Engine-independent statistics collected
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test.t1 analyze status OK
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create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
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explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
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2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
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explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
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2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
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delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
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affected rows: 4
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select * from t1;
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c1 c2 c3
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1 2 2
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1 3 3
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11 2 12
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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12 5 18
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2 1 4
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2 2 5
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2 3 6
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2 4 7
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2 5 8
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21 3 22
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 5 27
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22 6 28
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31 3 32
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 5 37
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32 6 38
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insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
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drop table tmp;
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#
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# Delete with EXISTS subquery over the updated table
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# in WHERE + possibly sargable condition
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#
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analyze table t1 persistent for all;
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Table Op Msg_type Msg_text
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test.t1 analyze status Engine-independent statistics collected
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test.t1 analyze status OK
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create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
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explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
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1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
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explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
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1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
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analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
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id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 9.38 9.38 Using where
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1 PRIMARY a ALL NULL NULL NULL NULL 32 12.00 3.12 5.56 Using where; FirstMatch(t1)
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select * from t1;
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c1 c2 c3
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1 3 3
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11 1 11
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11 2 12
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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12 5 18
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2 1 4
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2 2 5
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2 3 6
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2 4 7
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2 5 8
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21 2 21
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21 3 22
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 5 27
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22 6 28
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31 2 31
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31 3 32
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 5 37
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32 6 38
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insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
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drop table tmp;
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#
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# Delete with IN predicand over the updated table in WHERE
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#
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create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
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explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32
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1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
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explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32
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1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
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delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
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affected rows: 8
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select * from t1;
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c1 c2 c3
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1 3 3
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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12 5 18
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2 1 4
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2 2 5
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2 3 6
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2 4 7
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2 5 8
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 5 27
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22 6 28
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 5 37
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32 6 38
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insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
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drop table tmp;
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#
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# Delete with a limit - can be deleted
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#
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create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
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explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
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1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
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explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
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1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
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analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
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id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 12.50 Using where
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1 PRIMARY a ALL NULL NULL NULL NULL 32 24.50 3.12 1.02 Using where; FirstMatch(t1)
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select * from t1;
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c1 c2 c3
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1 2 2
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1 3 3
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11 1 11
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11 2 12
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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12 5 18
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2 1 4
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2 2 5
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2 3 6
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2 4 7
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2 5 8
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21 2 21
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21 3 22
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 5 27
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22 6 28
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31 2 31
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31 3 32
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 5 37
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32 6 38
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insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
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drop table tmp;
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#
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# Delete with a limit and an order by
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#
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create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
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order by c3 desc limit 1;
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explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
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order by c3 desc limit 1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort
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1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
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explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
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order by c3 desc limit 1;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using filesort
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1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
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delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
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order by c3 desc limit 1;
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affected rows: 1
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select * from t1;
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c1 c2 c3
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1 1 1
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1 2 2
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1 3 3
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11 1 11
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11 2 12
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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12 5 18
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2 1 4
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2 3 6
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2 4 7
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2 5 8
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21 2 21
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21 3 22
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 5 27
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22 6 28
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31 2 31
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31 3 32
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 5 37
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32 6 38
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insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
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drop table tmp;
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#
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# Delete: 2 execution of PS
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#
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prepare create_tmp_stmt from
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"create table tmp as select * from t1
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where c2=(select a.c3 from t1 a where a.c3 = ?)";
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prepare delete_t1_stmt from
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"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
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set @a:=5;
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execute create_tmp_stmt using @a;
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execute delete_t1_stmt using @a;
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execute delete_t1_stmt using @a;
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select * from t1;
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c1 c2 c3
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1 1 1
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1 2 2
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1 3 3
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11 1 11
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11 2 12
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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2 1 4
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2 2 5
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2 3 6
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2 4 7
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21 2 21
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21 3 22
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 6 28
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31 2 31
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31 3 32
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 6 38
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prepare insert_tmp_stmt from
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"insert into tmp(c1,c2,c3) select * from t1
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where c2=(select a.c3 from t1 a where a.c3 = ?)";
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set @a:=2;
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execute insert_tmp_stmt using @a;
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execute delete_t1_stmt using @a;
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select * from t1;
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c1 c2 c3
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1 1 1
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1 3 3
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11 1 11
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11 3 13
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12 1 14
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12 3 16
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12 4 17
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2 1 4
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2 3 6
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2 4 7
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21 3 22
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21 4 23
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22 3 25
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22 4 26
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22 6 28
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31 3 32
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31 4 33
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32 3 35
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32 4 36
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32 6 38
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insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
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select * from t1;
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c1 c2 c3
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1 1 1
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1 2 2
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1 3 3
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11 1 11
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11 2 12
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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12 5 18
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2 1 4
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2 2 5
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2 3 6
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2 4 7
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2 5 8
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21 2 21
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21 3 22
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 5 27
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22 6 28
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31 2 31
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31 3 32
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 5 37
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32 6 38
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drop table tmp;
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#
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# Delete in stored procedure
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#
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create procedure sp()
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begin
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delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
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order by c3 desc limit 1;
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end
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//
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create table tmp as select * from t1
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where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
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order by c3 desc limit 1;
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CALL sp;
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insert into tmp(c1,c2,c3) select * from t1
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where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
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order by c3 desc limit 1;
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CALL sp;
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insert into tmp(c1,c2,c3) select * from t1
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where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
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order by c3 desc limit 1;
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CALL sp;
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select * from t1;
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c1 c2 c3
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1 2 2
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1 3 3
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11 1 11
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11 2 12
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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12 5 18
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2 1 4
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2 3 6
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2 4 7
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2 5 8
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21 2 21
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21 3 22
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 5 27
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22 6 28
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31 2 31
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31 3 32
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 5 37
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32 6 38
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insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
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drop procedure sp;
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drop table tmp;
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#
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# Delete in stored function
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#
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create function f1(IN a INT) returns int
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begin
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delete from t1 where c3 < a order by c3 limit 1;
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return 1;
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end;//
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set @a:=7;
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create table tmp as select * from t1 where c3 < @a
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order by c3 limit 1;
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select f1(@a);
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f1(@a)
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1
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insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
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order by c3 limit 1;
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select f1(@a);
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f1(@a)
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1
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select * from t1;
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c1 c2 c3
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1 3 3
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11 1 11
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11 2 12
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11 3 13
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12 1 14
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12 2 15
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12 3 16
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12 4 17
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12 5 18
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2 1 4
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2 2 5
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2 3 6
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2 4 7
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2 5 8
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21 2 21
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21 3 22
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21 4 23
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22 2 24
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22 3 25
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22 4 26
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22 5 27
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22 6 28
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31 2 31
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31 3 32
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31 4 33
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32 2 34
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32 3 35
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32 4 36
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32 5 37
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32 6 38
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insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
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drop function f1;
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drop table tmp;
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#
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# Delete in trigger
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#
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create table t2 (c1 integer);
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insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
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CREATE TABLE cnt(del integer);
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INSERT INTO cnt VALUES(0);
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CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
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UPDATE cnt SET del=del+1;
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CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
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DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
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CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
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DELETE FROM t1 WHERE c2>=3;
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affected rows: 20
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select * from t1;
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c1 c2 c3
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1 1 1
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1 2 2
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11 1 11
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11 2 12
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12 1 14
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12 2 15
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2 1 4
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2 2 5
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21 2 21
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22 2 24
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31 2 31
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|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 32.00 25.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#######################################
|
|
# Test with an index #
|
|
#######################################
|
|
create index t1_c2 on t1 (c2,c1);
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 Using where; Using index; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 Using where; Using index; FirstMatch(t1)
|
|
analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 32.00 9.38 9.38 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 11.67 3.12 5.71 Using where; Using index; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 10 test.t1.c2,test.t1.c3 1 Using index; FirstMatch(t1)
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 10 test.t1.c2,test.t1.c3 1 Using index; FirstMatch(t1)
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 Using index; FirstMatch(t1)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 Using index; FirstMatch(t1)
|
|
analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 12.50 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 0.25 18.75 100.00 Using index; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using filesort
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 Using index
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 Using index
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 1.00 100.00 100.00 Using index
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#######################################
|
|
# Test with a primary key #
|
|
#######################################
|
|
drop index t1_c2 on t1;
|
|
alter table t1 add primary key (c3);
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 9.38 9.38 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 12.33 3.12 5.41 Using where; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c1 1 Using where; End temporary
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c1 1 Using where; End temporary
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 Using where; End temporary
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 Using where; End temporary
|
|
analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 1.00 100.00 100.00 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 1.00 3.12 100.00 Using where; End temporary
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 index PRIMARY PRIMARY 4 NULL 1
|
|
1 PRIMARY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using where
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 index PRIMARY PRIMARY 4 NULL 1
|
|
1 PRIMARY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using where
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 32.00 25.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
drop view v1;
|
|
drop table t1;
|
|
#
|
|
# Test on dynamic columns (blob)
|
|
#
|
|
create table assets (
|
|
item_name varchar(32) primary key, -- A common attribute for all items
|
|
dynamic_cols blob -- Dynamic columns will be stored here
|
|
);
|
|
INSERT INTO assets
|
|
VALUES ('MariaDB T-shirt',
|
|
COLUMN_CREATE('color', 'blue', 'size', 'XL'));
|
|
INSERT INTO assets
|
|
VALUES ('Thinkpad Laptop',
|
|
COLUMN_CREATE('color', 'black', 'price', 500));
|
|
INSERT INTO assets
|
|
VALUES ('Fridge',
|
|
COLUMN_CREATE('color', 'white', 'warranty', '5 years'));
|
|
INSERT INTO assets
|
|
VALUES ('Microwave',
|
|
COLUMN_CREATE('warranty', '3 years'));
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge white
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
Thinkpad Laptop black
|
|
UPDATE assets SET dynamic_cols=COLUMN_DELETE(dynamic_cols, 'color')
|
|
WHERE item_name='Fridge';
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
Thinkpad Laptop black
|
|
DELETE FROM assets
|
|
WHERE item_name in
|
|
(select b.item_name from assets b
|
|
where COLUMN_GET(b.dynamic_cols, 'color' as char) ='black');
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
DELETE FROM assets WHERE item_name='Microwave';
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
drop table assets ;
|
|
#
|
|
# Test on fulltext columns
|
|
#
|
|
CREATE TABLE ft2(copy TEXT,FULLTEXT(copy));
|
|
INSERT INTO ft2(copy) VALUES
|
|
('MySQL vs MariaDB database'),
|
|
('Oracle vs MariaDB database'),
|
|
('PostgreSQL vs MariaDB database'),
|
|
('MariaDB overview'),
|
|
('Foreign keys'),
|
|
('Primary keys'),
|
|
('Indexes'),
|
|
('Transactions'),
|
|
('Triggers');
|
|
SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
copy
|
|
MySQL vs MariaDB database
|
|
Oracle vs MariaDB database
|
|
PostgreSQL vs MariaDB database
|
|
DELETE FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
copy
|
|
drop table ft2;
|
|
#######################################
|
|
# #
|
|
# Engine Aria #
|
|
# #
|
|
#######################################
|
|
set default_storage_engine=Aria;
|
|
create table t1 (c1 integer, c2 integer, c3 integer);
|
|
insert into t1(c1,c2,c3)
|
|
values (1,1,1),(1,2,2),(1,3,3),
|
|
(2,1,4),(2,2,5),(2,3,6),
|
|
(2,4,7),(2,5,8);
|
|
insert into t1 select c1+10,c2,c3+10 from t1;
|
|
insert into t1 select c1+20,c2+1,c3+20 from t1;
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create view v1 as select * from t1 where c2=2;
|
|
#######################################
|
|
# Test without any index #
|
|
#######################################
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status Table is already up to date
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 9.38 9.38 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 12.67 3.12 5.26 Using where; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 25.00 100.00 12.00 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 22.67 3.12 1.47 Using where; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using filesort
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 32.00 25.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where; Using filesort
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func #
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL #
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func #
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL #
|
|
analyze delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # 32.00 62.50 62.50 Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func # 1.00 100.00 100.00
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL # 32.00 62.50 100.00
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status Table is already up to date
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # Using where
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL # Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # Using where
|
|
analyze delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # 32.00 3.91 3.12 Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL # 5.00 25.00 20.00 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # 32.00 100.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#######################################
|
|
# Test with an index #
|
|
#######################################
|
|
create index t1_c2 on t1 (c2,c1);
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 Using where; Using index; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 Using where; Using index; FirstMatch(t1)
|
|
analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 32.00 9.38 9.38 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 11.67 3.12 5.71 Using where; Using index; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 10 test.t1.c2,test.t1.c3 1 Using index; FirstMatch(t1)
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 10 test.t1.c2,test.t1.c3 1 Using index; FirstMatch(t1)
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 Using index; FirstMatch(t1)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 Using index; FirstMatch(t1)
|
|
analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 27.00 100.00 14.81 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 0.25 18.75 100.00 Using index; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where; Using filesort
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 Using where; FirstMatch(t1)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where; Using filesort
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 Using index
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 Using index
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 1.00 100.00 100.00 Using index
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 const 8
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 const 8 Using index; FirstMatch(t1)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 const 8
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 const 8 Using index; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 range t1_c2 t1_c2 5 NULL # Using index condition
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c2 # Using index; FirstMatch(t1)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a index t1_c2 t1_c2 10 NULL # Using where; Using index; LooseScan
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 #
|
|
analyze delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY a index t1_c2 t1_c2 10 NULL # 16.00 20.00 25.00 Using where; Using index; LooseScan
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 # 5.00 4.76 100.00
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 const 8 Using where
|
|
2 DEPENDENT SUBQUERY a ref t1_c2 t1_c2 5 test.t1.c2 5 Using index
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 const 8 Using where
|
|
2 DEPENDENT SUBQUERY a ref t1_c2 t1_c2 5 test.t1.c2 5 Using index
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status Table is already up to date
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const # Using where
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const # Using index; FirstMatch(t1)
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # Using where
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const # Using where
|
|
3 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,func # Using where; Using index
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # Using where
|
|
analyze delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const # 1.00 100.00 100.00 Using where
|
|
3 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,func # 1.00 100.00 100.00 Using where; Using index
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # 32.00 100.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#######################################
|
|
# Test with a primary key #
|
|
#######################################
|
|
drop index t1_c2 on t1;
|
|
alter table t1 add primary key (c3);
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using index
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using index
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 9.38 9.38 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 13.33 3.12 5.00 Using where; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c1 1 Using where; End temporary
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c1 1 Using where; End temporary
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 Using where; End temporary
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 Using where; End temporary
|
|
analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 4.00 100.00 100.00 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 1.00 3.12 25.00 Using where; End temporary
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 index PRIMARY PRIMARY 4 NULL 1
|
|
1 PRIMARY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using where
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 index PRIMARY PRIMARY 4 NULL 1
|
|
1 PRIMARY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using where
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 32.00 25.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where; Using filesort
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func #
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL #
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func #
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL #
|
|
analyze delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # 32.00 62.50 62.50 Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func # 1.00 100.00 100.00
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL # 32.00 62.50 100.00
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 const PRIMARY PRIMARY 4 const 1
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 const PRIMARY PRIMARY 4 const 1
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status Table is already up to date
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 #
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL # Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 #
|
|
analyze delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # 32.00 3.91 3.12 Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL # 10.00 25.00 10.00 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 # 1.00 100.00 100.00
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
drop view v1;
|
|
drop table t1;
|
|
#
|
|
# Test on dynamic columns (blob)
|
|
#
|
|
create table assets (
|
|
item_name varchar(32) primary key, -- A common attribute for all items
|
|
dynamic_cols blob -- Dynamic columns will be stored here
|
|
);
|
|
INSERT INTO assets
|
|
VALUES ('MariaDB T-shirt',
|
|
COLUMN_CREATE('color', 'blue', 'size', 'XL'));
|
|
INSERT INTO assets
|
|
VALUES ('Thinkpad Laptop',
|
|
COLUMN_CREATE('color', 'black', 'price', 500));
|
|
INSERT INTO assets
|
|
VALUES ('Fridge',
|
|
COLUMN_CREATE('color', 'white', 'warranty', '5 years'));
|
|
INSERT INTO assets
|
|
VALUES ('Microwave',
|
|
COLUMN_CREATE('warranty', '3 years'));
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge white
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
Thinkpad Laptop black
|
|
UPDATE assets SET dynamic_cols=COLUMN_DELETE(dynamic_cols, 'color')
|
|
WHERE item_name='Fridge';
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
Thinkpad Laptop black
|
|
DELETE FROM assets
|
|
WHERE item_name in
|
|
(select b.item_name from assets b
|
|
where COLUMN_GET(b.dynamic_cols, 'color' as char) ='black');
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
DELETE FROM assets WHERE item_name='Microwave';
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
drop table assets ;
|
|
#
|
|
# Test on fulltext columns
|
|
#
|
|
CREATE TABLE ft2(copy TEXT,FULLTEXT(copy));
|
|
INSERT INTO ft2(copy) VALUES
|
|
('MySQL vs MariaDB database'),
|
|
('Oracle vs MariaDB database'),
|
|
('PostgreSQL vs MariaDB database'),
|
|
('MariaDB overview'),
|
|
('Foreign keys'),
|
|
('Primary keys'),
|
|
('Indexes'),
|
|
('Transactions'),
|
|
('Triggers');
|
|
SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
copy
|
|
MySQL vs MariaDB database
|
|
Oracle vs MariaDB database
|
|
PostgreSQL vs MariaDB database
|
|
DELETE FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
copy
|
|
drop table ft2;
|
|
#######################################
|
|
# #
|
|
# Engine MyISAM #
|
|
# #
|
|
#######################################
|
|
set default_storage_engine=MyISAM;
|
|
create table t1 (c1 integer, c2 integer, c3 integer);
|
|
insert into t1(c1,c2,c3)
|
|
values (1,1,1),(1,2,2),(1,3,3),
|
|
(2,1,4),(2,2,5),(2,3,6),
|
|
(2,4,7),(2,5,8);
|
|
insert into t1 select c1+10,c2,c3+10 from t1;
|
|
insert into t1 select c1+20,c2+1,c3+20 from t1;
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create view v1 as select * from t1 where c2=2;
|
|
#######################################
|
|
# Test without any index #
|
|
#######################################
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status Table is already up to date
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 9.38 9.38 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 12.67 3.12 5.26 Using where; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 25.00 100.00 12.00 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 22.67 3.12 1.47 Using where; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using filesort
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 32.00 25.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where; Using filesort
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func #
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL #
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func #
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL #
|
|
analyze delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # 32.00 62.50 62.50 Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func # 1.00 100.00 100.00
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL # 32.00 62.50 100.00
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status Table is already up to date
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # Using where
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL # Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # Using where
|
|
analyze delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # 32.00 3.91 3.12 Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL # 5.00 25.00 20.00 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # 32.00 100.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#######################################
|
|
# Test with an index #
|
|
#######################################
|
|
create index t1_c2 on t1 (c2,c1);
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 Using where; Using index; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 Using where; Using index; FirstMatch(t1)
|
|
analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 32.00 9.38 9.38 Using where
|
|
1 PRIMARY a index NULL t1_c2 10 NULL 32 11.67 3.12 5.71 Using where; Using index; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 10 test.t1.c2,test.t1.c3 1 Using index; FirstMatch(t1)
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 10 test.t1.c2,test.t1.c3 1 Using index; FirstMatch(t1)
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 Using index; FirstMatch(t1)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 Using index; FirstMatch(t1)
|
|
analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 29.00 100.00 13.79 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c1 5 0.25 18.75 100.00 Using index; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using filesort
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 Using index
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 Using index
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 1 1.00 100.00 100.00 Using index
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 const 8
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 const 8 Using index; FirstMatch(t1)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 const 8
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 const 8 Using index; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL # Using where; Using filesort
|
|
1 PRIMARY a ref t1_c2 t1_c2 5 test.t1.c2 # Using index; FirstMatch(t1)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a index t1_c2 t1_c2 10 NULL # Using where; Using index; LooseScan
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 #
|
|
analyze delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY a index t1_c2 t1_c2 10 NULL # 16.00 20.00 25.00 Using where; Using index; LooseScan
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 test.a.c2 # 5.00 5.00 100.00
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 const 8 Using where
|
|
2 DEPENDENT SUBQUERY a ref t1_c2 t1_c2 5 test.t1.c2 5 Using index
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 5 const 8 Using where
|
|
2 DEPENDENT SUBQUERY a ref t1_c2 t1_c2 5 test.t1.c2 5 Using index
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status Table is already up to date
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const # Using where
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const # Using index; FirstMatch(t1)
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # Using where
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const # Using where
|
|
3 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,func # Using where; Using index
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # Using where
|
|
analyze delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const # 1.00 100.00 100.00 Using where
|
|
3 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,func # 1.00 100.00 100.00 Using where; Using index
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL # 32.00 100.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#######################################
|
|
# Test with a primary key #
|
|
#######################################
|
|
drop index t1_c2 on t1;
|
|
alter table t1 add primary key (c3);
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using index
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using index
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
analyze delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 9.38 9.38 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 14.00 3.12 4.76 Using where; FirstMatch(t1)
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c1 1 Using where; End temporary
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c1 1 Using where; End temporary
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 Using where; End temporary
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 Using where; End temporary
|
|
analyze delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 4.00 100.00 100.00 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 1.00 3.12 25.00 Using where; End temporary
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 index PRIMARY PRIMARY 4 NULL 1
|
|
1 PRIMARY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using where
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 index PRIMARY PRIMARY 4 NULL 1
|
|
1 PRIMARY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using where
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
# Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
analyze delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 32.00 100.00 25.00 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 32.00 25.00 3.12 Using where
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where; Using filesort
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func #
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL #
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func #
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL #
|
|
analyze delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # 32.00 62.50 62.50 Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func # 1.00 100.00 100.00
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL # 32.00 62.50 100.00
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status OK
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 const PRIMARY PRIMARY 4 const 1
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 const PRIMARY PRIMARY 4 const 1
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze status Table is already up to date
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 #
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL # Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 #
|
|
analyze delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL # 32.00 3.91 3.12 Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL # 3.00 25.00 33.33 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 # 1.00 100.00 100.00
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
drop view v1;
|
|
drop table t1;
|
|
#
|
|
# Test on dynamic columns (blob)
|
|
#
|
|
create table assets (
|
|
item_name varchar(32) primary key, -- A common attribute for all items
|
|
dynamic_cols blob -- Dynamic columns will be stored here
|
|
);
|
|
INSERT INTO assets
|
|
VALUES ('MariaDB T-shirt',
|
|
COLUMN_CREATE('color', 'blue', 'size', 'XL'));
|
|
INSERT INTO assets
|
|
VALUES ('Thinkpad Laptop',
|
|
COLUMN_CREATE('color', 'black', 'price', 500));
|
|
INSERT INTO assets
|
|
VALUES ('Fridge',
|
|
COLUMN_CREATE('color', 'white', 'warranty', '5 years'));
|
|
INSERT INTO assets
|
|
VALUES ('Microwave',
|
|
COLUMN_CREATE('warranty', '3 years'));
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge white
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
Thinkpad Laptop black
|
|
UPDATE assets SET dynamic_cols=COLUMN_DELETE(dynamic_cols, 'color')
|
|
WHERE item_name='Fridge';
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
Thinkpad Laptop black
|
|
DELETE FROM assets
|
|
WHERE item_name in
|
|
(select b.item_name from assets b
|
|
where COLUMN_GET(b.dynamic_cols, 'color' as char) ='black');
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
Microwave NULL
|
|
DELETE FROM assets WHERE item_name='Microwave';
|
|
SELECT item_name, COLUMN_GET(dynamic_cols, 'color' as char) AS color
|
|
FROM assets ORDER BY item_name;
|
|
item_name color
|
|
Fridge NULL
|
|
MariaDB T-shirt blue
|
|
drop table assets ;
|
|
#
|
|
# Test on fulltext columns
|
|
#
|
|
CREATE TABLE ft2(copy TEXT,FULLTEXT(copy));
|
|
INSERT INTO ft2(copy) VALUES
|
|
('MySQL vs MariaDB database'),
|
|
('Oracle vs MariaDB database'),
|
|
('PostgreSQL vs MariaDB database'),
|
|
('MariaDB overview'),
|
|
('Foreign keys'),
|
|
('Primary keys'),
|
|
('Indexes'),
|
|
('Transactions'),
|
|
('Triggers');
|
|
SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
copy
|
|
MySQL vs MariaDB database
|
|
Oracle vs MariaDB database
|
|
PostgreSQL vs MariaDB database
|
|
DELETE FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database');
|
|
copy
|
|
drop table ft2;
|
|
#######################################
|
|
# #
|
|
# Engine MEMORY #
|
|
# #
|
|
#######################################
|
|
set default_storage_engine=MEMORY;
|
|
create table t1 (c1 integer, c2 integer, c3 integer);
|
|
insert into t1(c1,c2,c3)
|
|
values (1,1,1),(1,2,2),(1,3,3),
|
|
(2,1,4),(2,2,5),(2,3,6),
|
|
(2,4,7),(2,5,8);
|
|
insert into t1 select c1+10,c2,c3+10 from t1;
|
|
insert into t1 select c1+20,c2+1,c3+20 from t1;
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create view v1 as select * from t1 where c2=2;
|
|
#######################################
|
|
# Test without any index #
|
|
#######################################
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
affected rows: 2
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where; Using filesort
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL 32
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL 32
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using filesort
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#######################################
|
|
# Test with an index #
|
|
#######################################
|
|
create index t1_c2 on t1 (c2,c1);
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Operation failed
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Operation failed
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
affected rows: 2
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Operation failed
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Operation failed
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where; Using filesort
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
|
2 MATERIALIZED a ALL t1_c2 NULL NULL NULL 32
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
|
2 MATERIALIZED a ALL t1_c2 NULL NULL NULL 32
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 10 test.t1.c2,test.t1.c3 2 FirstMatch(t1)
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ref t1_c2 t1_c2 10 test.t1.c2,test.t1.c3 2 FirstMatch(t1)
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using temporary; Using filesort
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using filesort
|
|
1 PRIMARY a ALL t1_c2 NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 2
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,test.t1.c1 2
|
|
delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Operation failed
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL t1_c2 NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL t1_c2 NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a ALL t1_c2 NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Operation failed
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const 2 Using where
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const 2 FirstMatch(t1)
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ref t1_c2 t1_c2 10 const,const 2 Using where
|
|
3 DEPENDENT SUBQUERY t1 ref t1_c2 t1_c2 10 const,func 2 Using where
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#######################################
|
|
# Test with a primary key #
|
|
#######################################
|
|
drop index t1_c2 on t1;
|
|
alter table t1 add primary key (c3);
|
|
#
|
|
# Delete with value from subquery on the same table
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
explain select * from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1
|
|
explain delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1
|
|
delete from t1 where c1=(select a.c3 from t1 a where a.c3 = t1.c3);
|
|
affected rows: 4
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + possibly sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
explain select * from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where c1 = 1 and exists (select 'X' from t1 a where a.c1 = t1.c2);
|
|
affected rows: 2
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with EXISTS subquery over the updated table
|
|
# in WHERE + non-sargable condition
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1)
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 = 3;
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 4 23
|
|
22 2 24
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 4 33
|
|
32 2 34
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with order by
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
explain select * from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where; Using filesort
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL 32
|
|
explain delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
|
2 MATERIALIZED a ALL NULL NULL NULL NULL 32
|
|
delete from t1 where exists (select 'X' from t1 a where a.c2 = t1.c2)
|
|
and c2 >= 3 order by c2;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with IN predicand over the updated table in WHERE
|
|
#
|
|
create table tmp as select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
explain select * from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c1 1 Using where; End temporary
|
|
explain delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c1 1 Using where; End temporary
|
|
delete from t1 where c3 in (select distinct a.c1 from t1 a where t1.c2=a.c2);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit - can be deleted
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 Using where; End temporary
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY a ALL NULL NULL NULL NULL 32 Using where; Start temporary
|
|
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 test.a.c2 1 Using where; End temporary
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c2 = t1.c3) limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete with a limit and an order by
|
|
#
|
|
create table tmp as select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
explain select * from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL PRIMARY NULL NULL NULL 32 Using filesort
|
|
1 PRIMARY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using where
|
|
explain delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL PRIMARY NULL NULL NULL 32 Using filesort
|
|
1 PRIMARY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1 Using where
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete: 2 execution of PS
|
|
#
|
|
prepare create_tmp_stmt from
|
|
"create table tmp as select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
prepare delete_t1_stmt from
|
|
"delete from t1 where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=5;
|
|
execute create_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
prepare insert_tmp_stmt from
|
|
"insert into tmp(c1,c2,c3) select * from t1
|
|
where c2=(select a.c3 from t1 a where a.c3 = ?)";
|
|
set @a:=2;
|
|
execute insert_tmp_stmt using @a;
|
|
execute delete_t1_stmt using @a;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored procedure
|
|
#
|
|
create procedure sp()
|
|
begin
|
|
delete from t1 where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
end
|
|
//
|
|
create table tmp as select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
insert into tmp(c1,c2,c3) select * from t1
|
|
where c1 in (select a.c2 from t1 a where a.c3 = t1.c3)
|
|
order by c3 desc limit 1;
|
|
CALL sp;
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop procedure sp;
|
|
drop table tmp;
|
|
#
|
|
# Delete in stored function
|
|
#
|
|
create function f1(IN a INT) returns int
|
|
begin
|
|
delete from t1 where c3 < a order by c3 limit 1;
|
|
return 1;
|
|
end;//
|
|
set @a:=7;
|
|
create table tmp as select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
insert into tmp(c1,c2,c3) select * from t1 where c3 < @a
|
|
order by c3 limit 1;
|
|
select f1(@a);
|
|
f1(@a)
|
|
1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop function f1;
|
|
drop table tmp;
|
|
#
|
|
# Delete in trigger
|
|
#
|
|
create table t2 (c1 integer);
|
|
insert into t2(c1) values (1), (2), (3), (4), (5), (6), (7), (8);
|
|
CREATE TABLE cnt(del integer);
|
|
INSERT INTO cnt VALUES(0);
|
|
CREATE TRIGGER tr1 AFTER DELETE ON t1 FOR EACH ROW
|
|
UPDATE cnt SET del=del+1;
|
|
CREATE TRIGGER tr2 AFTER DELETE ON t1 FOR EACH ROW
|
|
DELETE FROM t2 WHERE c1> (SELECT count(*)-1 FROM t2);
|
|
CREATE TABLE tmp as SELECT * FROM t1 WHERE c2>=3;
|
|
DELETE FROM t1 WHERE c2>=3;
|
|
affected rows: 20
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
11 1 11
|
|
11 2 12
|
|
12 1 14
|
|
12 2 15
|
|
2 1 4
|
|
2 2 5
|
|
21 2 21
|
|
22 2 24
|
|
31 2 31
|
|
32 2 34
|
|
SELECT * FROM t2;
|
|
c1
|
|
SELECT * FROM cnt;
|
|
del
|
|
20
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
DROP TRIGGER tr1;
|
|
DROP TRIGGER tr2;
|
|
drop table t2, cnt, tmp;
|
|
#
|
|
Delete with a reference to view in subquery
|
|
#
|
|
create table tmp as select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
explain select * from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
delete from t1 where t1.c2 in ( select max(a.c2) from v1 a
|
|
where a.c1 = t1.c1);
|
|
affected rows: 8
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 3 3
|
|
11 1 11
|
|
11 3 13
|
|
12 1 14
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 3 22
|
|
21 4 23
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 3 32
|
|
31 4 33
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
explain select * from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 const PRIMARY PRIMARY 4 const 1
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
explain delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 const PRIMARY PRIMARY 4 const 1
|
|
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 32 Using where
|
|
delete from v1 where v1.c1 in
|
|
(select max(a.c1) from t1 a where a.c2 = v1.c2) and c3 = 5;
|
|
affected rows: 0
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 2 5
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
#
|
|
# Delete from view using reference
|
|
# to the same view in subquery
|
|
#
|
|
analyze table t1 persistent for all;
|
|
Table Op Msg_type Msg_text
|
|
test.t1 analyze status Engine-independent statistics collected
|
|
test.t1 analyze note The storage engine for the table doesn't support analyze
|
|
create table tmp as select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
explain select * from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1
|
|
explain delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
3 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 32 Using where
|
|
2 DEPENDENT SUBQUERY a eq_ref PRIMARY PRIMARY 4 test.t1.c3 1
|
|
delete from v1 where v1.c2 in (select max(a.c2) from t1 a where a.c3 = v1.c3)
|
|
and c1 = 2
|
|
and exists (select 'X' from v1 a where a.c1 = v1.c1);
|
|
affected rows: 1
|
|
select * from t1;
|
|
c1 c2 c3
|
|
1 1 1
|
|
1 2 2
|
|
1 3 3
|
|
11 1 11
|
|
11 2 12
|
|
11 3 13
|
|
12 1 14
|
|
12 2 15
|
|
12 3 16
|
|
12 4 17
|
|
12 5 18
|
|
2 1 4
|
|
2 3 6
|
|
2 4 7
|
|
2 5 8
|
|
21 2 21
|
|
21 3 22
|
|
21 4 23
|
|
22 2 24
|
|
22 3 25
|
|
22 4 26
|
|
22 5 27
|
|
22 6 28
|
|
31 2 31
|
|
31 3 32
|
|
31 4 33
|
|
32 2 34
|
|
32 3 35
|
|
32 4 36
|
|
32 5 37
|
|
32 6 38
|
|
insert into t1(c1,c2,c3) select c1,c2,c3 from tmp;
|
|
drop table tmp;
|
|
drop view v1;
|
|
drop table t1;
|
|
set @@default_storage_engine=@save_default_engine;
|
|
#
|
|
# End of 11.0 tests
|
|
#
|