mirror of
https://github.com/MariaDB/server.git
synced 2025-01-19 13:32:33 +01:00
28962a76a3
To correctly decide which predicates can be evaluated with a given table the optimizer must know the exact set of tables that a predicate depends on. If that mask is too wide (refer to non-existing tables) the optimizer can erroneously skip a predicate. One such case of wrong table usage mask were the aggregate functions. The have a all-1 mask (meaning depend on all tables, including non-existent ones). Fixed by making a real used_tables mask for the aggregates. The mask is constructed in the following way : 1. OR the table dependency masks of all the arguments of the aggregate. 2. If all the arguments of the function are from the local name resolution context and it is evaluated in the same name resolution context where it is referenced all the tables from that name resolution context are OR-ed to the dependency mask. This is to denote that an aggregate function depends on the number of rows it processes. 3. Handle correctly the case of an aggregate function optimization (such that the aggregate function can be pre-calculated and made a constant). Made sure that an aggregate function is never a constant (unless subject of a specific optimization and pre-calculation). One other flaw was revealed and fixed in the process : references were not calling the recalculation method for used_tables of their targets.
700 lines
24 KiB
Text
700 lines
24 KiB
Text
drop table if exists t0, t1, t2, t3, t4;
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create table t1 (oref int, grp int, ie int) ;
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insert into t1 (oref, grp, ie) values
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(1, 1, 1),
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(1, 1, 1),
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(1, 2, NULL),
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(2, 1, 3),
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(3, 1, 4),
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(3, 2, NULL);
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create table t2 (oref int, a int);
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insert into t2 values
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(1, 1),
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(2, 2),
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(3, 3),
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(4, NULL),
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(2, NULL);
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select a, oref, a in (select max(ie)
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from t1 where oref=t2.oref group by grp) Z from t2;
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a oref Z
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1 1 1
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2 2 0
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3 3 NULL
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NULL 4 0
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NULL 2 NULL
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explain extended
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select a, oref, a in (select max(ie)
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from t1 where oref=t2.oref group by grp) Z from t2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 5
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2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 6 Using where; Using temporary; Using filesort
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Warnings:
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Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>(`test`.`t2`.`a`,<exists>(select max(`test`.`t1`.`ie`) AS `max(ie)` from `test`.`t1` where (`test`.`t1`.`oref` = `test`.`t2`.`oref`) group by `test`.`t1`.`grp` having trigcond((<cache>(`test`.`t2`.`a`) = <ref_null_helper>(max(`test`.`t1`.`ie`)))))) AS `Z` from `test`.`t2`
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explain extended
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select a, oref from t2
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where a in (select max(ie) from t1 where oref=t2.oref group by grp);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 5 Using where
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2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 6 Using where; Using temporary; Using filesort
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Warnings:
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Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`oref` AS `oref` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(select max(`test`.`t1`.`ie`) AS `max(ie)` from `test`.`t1` where (`test`.`t1`.`oref` = `test`.`t2`.`oref`) group by `test`.`t1`.`grp` having (<cache>(`test`.`t2`.`a`) = <ref_null_helper>(max(`test`.`t1`.`ie`)))))
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select a, oref, a in (
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select max(ie) from t1 where oref=t2.oref group by grp union
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select max(ie) from t1 where oref=t2.oref group by grp
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) Z from t2;
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a oref Z
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1 1 1
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2 2 0
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3 3 NULL
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NULL 4 0
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NULL 2 NULL
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create table t3 (a int);
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insert into t3 values (NULL), (NULL);
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flush status;
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select a in (select max(ie) from t1 where oref=4 group by grp) from t3;
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a in (select max(ie) from t1 where oref=4 group by grp)
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0
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0
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show status like 'Handler_read_rnd_next';
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Variable_name Value
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Handler_read_rnd_next 11
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select ' ^ This must show 11' Z;
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Z
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^ This must show 11
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explain extended select a in (select max(ie) from t1 where oref=4 group by grp) from t3;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t3 ALL NULL NULL NULL NULL 2
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2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 6 Using where; Using temporary; Using filesort
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Warnings:
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Note 1003 select <in_optimizer>(`test`.`t3`.`a`,<exists>(select max(`test`.`t1`.`ie`) AS `max(ie)` from `test`.`t1` where (`test`.`t1`.`oref` = 4) group by `test`.`t1`.`grp` having trigcond((<cache>(`test`.`t3`.`a`) = <ref_null_helper>(max(`test`.`t1`.`ie`)))))) AS `a in (select max(ie) from t1 where oref=4 group by grp)` from `test`.`t3`
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drop table t1, t2, t3;
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create table t1 (a int, oref int, key(a));
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insert into t1 values
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(1, 1),
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(1, NULL),
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(2, 3),
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(2, NULL),
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(3, NULL);
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create table t2 (a int, oref int);
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insert into t2 values (1, 1), (2,2), (NULL, 3), (NULL, 4);
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select oref, a, a in (select a from t1 where oref=t2.oref) Z from t2;
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oref a Z
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1 1 1
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2 2 0
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3 NULL NULL
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4 NULL 0
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explain extended
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select oref, a, a in (select a from t1 where oref=t2.oref) Z from t2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 4
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2 DEPENDENT SUBQUERY t1 index_subquery a a 5 func 2 Using where; Full scan on NULL key
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Warnings:
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Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t2`.`oref` AS `oref`,`test`.`t2`.`a` AS `a`,<in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a checking NULL where (`test`.`t1`.`oref` = `test`.`t2`.`oref`) having trigcond(<is_not_null_test>(`test`.`t1`.`a`))))) AS `Z` from `test`.`t2`
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flush status;
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select oref, a from t2 where a in (select a from t1 where oref=t2.oref);
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oref a
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1 1
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show status like '%Handler_read_rnd_next';
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Variable_name Value
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Handler_read_rnd_next 5
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delete from t2;
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insert into t2 values (NULL, 0),(NULL, 0), (NULL, 0), (NULL, 0);
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flush status;
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select oref, a, a in (select a from t1 where oref=t2.oref) Z from t2;
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oref a Z
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0 NULL 0
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0 NULL 0
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0 NULL 0
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0 NULL 0
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show status like '%Handler_read%';
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Variable_name Value
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Handler_read_first 0
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Handler_read_key 0
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Handler_read_next 0
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Handler_read_prev 0
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Handler_read_rnd 0
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Handler_read_rnd_next 29
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select 'No key lookups, seq reads: 29= 5 reads from t2 + 4 * 6 reads from t1.' Z;
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Z
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No key lookups, seq reads: 29= 5 reads from t2 + 4 * 6 reads from t1.
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drop table t1, t2;
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create table t1 (a int, b int, primary key (a));
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insert into t1 values (1,1), (3,1),(100,1);
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create table t2 (a int, b int);
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insert into t2 values (1,1),(2,1),(NULL,1),(NULL,0);
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select a,b, a in (select a from t1 where t1.b = t2.b) Z from t2 ;
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a b Z
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1 1 1
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2 1 0
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NULL 1 NULL
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NULL 0 0
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drop table t1, t2;
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create table t1 (a int, b int, key(a));
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insert into t1 values
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(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
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create table t2 like t1;
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insert into t2 select * from t1;
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update t2 set b=1;
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create table t3 (a int, oref int);
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insert into t3 values (1, 1), (NULL,1), (NULL,0);
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select a, oref,
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t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
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from t3;
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a oref Z
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1 1 1
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NULL 1 NULL
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NULL 0 0
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explain extended
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select a, oref,
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t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
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from t3;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t3 ALL NULL NULL NULL NULL 3
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2 DEPENDENT SUBQUERY t1 ref_or_null a a 5 func 4 Using where; Full scan on NULL key
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2 DEPENDENT SUBQUERY t2 ref a a 5 test.t1.b 1 Using where
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Warnings:
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Note 1276 Field or reference 't3.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t3`.`a` AS `a`,`test`.`t3`.`oref` AS `oref`,<in_optimizer>(`test`.`t3`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t1` join `test`.`t2` where ((`test`.`t2`.`a` = `test`.`t1`.`b`) and (`test`.`t2`.`b` = `test`.`t3`.`oref`) and trigcond(((<cache>(`test`.`t3`.`a`) = `test`.`t1`.`a`) or isnull(`test`.`t1`.`a`)))) having trigcond(<is_not_null_test>(`test`.`t1`.`a`)))) AS `Z` from `test`.`t3`
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drop table t1, t2, t3;
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create table t1 (a int NOT NULL, b int NOT NULL, key(a));
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insert into t1 values
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(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
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create table t2 like t1;
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insert into t2 select * from t1;
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update t2 set b=1;
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create table t3 (a int, oref int);
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insert into t3 values (1, 1), (NULL,1), (NULL,0);
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select a, oref,
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t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
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from t3;
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a oref Z
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1 1 1
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NULL 1 NULL
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NULL 0 0
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This must show a trig_cond:
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explain extended
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select a, oref,
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t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
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from t3;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t3 ALL NULL NULL NULL NULL 3
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2 DEPENDENT SUBQUERY t1 ref a a 4 func 2 Using where; Full scan on NULL key
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2 DEPENDENT SUBQUERY t2 ref a a 4 test.t1.b 1 Using where
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Warnings:
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Note 1276 Field or reference 't3.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t3`.`a` AS `a`,`test`.`t3`.`oref` AS `oref`,<in_optimizer>(`test`.`t3`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t1` join `test`.`t2` where ((`test`.`t2`.`a` = `test`.`t1`.`b`) and (`test`.`t2`.`b` = `test`.`t3`.`oref`) and trigcond((<cache>(`test`.`t3`.`a`) = `test`.`t1`.`a`))))) AS `Z` from `test`.`t3`
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drop table t1,t2,t3;
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create table t1 (oref int, grp int);
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insert into t1 (oref, grp) values
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(1, 1),
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(1, 1);
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create table t2 (oref int, a int);
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insert into t2 values
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(1, NULL),
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(2, NULL);
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select a, oref,
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a in (select count(*) from t1 group by grp having grp=t2.oref) Z from t2;
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a oref Z
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NULL 1 NULL
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NULL 2 0
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This must show a trig_cond:
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explain extended
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select a, oref,
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a in (select count(*) from t1 group by grp having grp=t2.oref) Z from t2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 2
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2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 2 Using temporary; Using filesort
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Warnings:
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Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>(`test`.`t2`.`a`,<exists>(select count(0) AS `count(*)` from `test`.`t1` group by `test`.`t1`.`grp` having ((`test`.`t1`.`grp` = `test`.`t2`.`oref`) and trigcond((<cache>(`test`.`t2`.`a`) = <ref_null_helper>(count(0))))))) AS `Z` from `test`.`t2`
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drop table t1, t2;
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create table t1 (a int, b int, primary key (a));
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insert into t1 values (1,1), (3,1),(100,1);
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create table t2 (a int, b int);
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insert into t2 values (1,1),(2,1),(NULL,1),(NULL,0);
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select a,b, a in (select a from t1 where t1.b = t2.b union select a from
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t1 where t1.b = t2.b) Z from t2 ;
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a b Z
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1 1 1
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2 1 0
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NULL 1 NULL
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NULL 0 0
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select a,b, a in (select a from t1 where t1.b = t2.b) Z from t2 ;
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a b Z
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1 1 1
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2 1 0
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NULL 1 NULL
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NULL 0 0
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drop table t1, t2;
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create table t3 (a int);
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insert into t3 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
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create table t2 (a int, b int, oref int);
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insert into t2 values (NULL,1, 100), (NULL,2, 100);
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create table t1 (a int, b int, c int, key(a,b));
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insert into t1 select 2*A, 2*A, 100 from t3;
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explain extended select a,b, oref, (a,b) in (select a,b from t1 where c=t2.oref) Z from t2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 2
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2 DEPENDENT SUBQUERY t1 index_subquery a a 5 func 2 Using where; Full scan on NULL key
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Warnings:
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Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`b`),<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a checking NULL where ((`test`.`t1`.`c` = `test`.`t2`.`oref`) and trigcond(((<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`) or isnull(`test`.`t1`.`a`))) and trigcond(((<cache>(`test`.`t2`.`b`) = `test`.`t1`.`b`) or isnull(`test`.`t1`.`b`)))) having (trigcond(<is_not_null_test>(`test`.`t1`.`a`)) and trigcond(<is_not_null_test>(`test`.`t1`.`b`)))))) AS `Z` from `test`.`t2`
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select a,b, oref, (a,b) in (select a,b from t1 where c=t2.oref) Z from t2;
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a b oref Z
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NULL 1 100 0
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NULL 2 100 NULL
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create table t4 (x int);
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insert into t4 select A.a + 10*B.a from t1 A, t1 B;
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explain extended
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select a,b, oref,
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(a,b) in (select a,b from t1,t4 where c=t2.oref) Z
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from t2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 2
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2 DEPENDENT SUBQUERY t1 ref_or_null a a 5 func 2 Using where; Full scan on NULL key
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2 DEPENDENT SUBQUERY t4 ALL NULL NULL NULL NULL 100 Using where
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Warnings:
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Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`b`),<exists>(select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` join `test`.`t4` where ((`test`.`t1`.`c` = `test`.`t2`.`oref`) and trigcond(((<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`) or isnull(`test`.`t1`.`a`))) and trigcond(((<cache>(`test`.`t2`.`b`) = `test`.`t1`.`b`) or isnull(`test`.`t1`.`b`)))) having (trigcond(<is_not_null_test>(`test`.`t1`.`a`)) and trigcond(<is_not_null_test>(`test`.`t1`.`b`))))) AS `Z` from `test`.`t2`
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select a,b, oref,
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(a,b) in (select a,b from t1,t4 where c=t2.oref) Z
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from t2;
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a b oref Z
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NULL 1 100 0
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NULL 2 100 NULL
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drop table t1,t2,t3,t4;
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create table t1 (oref char(4), grp int, ie1 int, ie2 int);
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insert into t1 (oref, grp, ie1, ie2) values
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('aa', 10, 2, 1),
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('aa', 10, 1, 1),
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('aa', 20, 2, 1),
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('bb', 10, 3, 1),
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('cc', 10, 4, 2),
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('cc', 20, 3, 2),
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('ee', 10, 2, 1),
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('ee', 10, 1, 2),
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('ff', 20, 2, 2),
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('ff', 20, 1, 2);
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create table t2 (oref char(4), a int, b int);
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insert into t2 values
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('ee', NULL, 1),
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('bb', 2, 1),
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('ff', 2, 2),
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('cc', 3, NULL),
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('bb', NULL, NULL),
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('aa', 1, 1),
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('dd', 1, NULL);
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alter table t1 add index idx(ie1,ie2);
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select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2 where a=3 and b is null ;
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oref a b Z
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cc 3 NULL NULL
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insert into t2 values ('new1', 10,10);
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insert into t1 values ('new1', 1234, 10, NULL);
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select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2 where a=10 and b=10;
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oref a b Z
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new1 10 10 NULL
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explain extended
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select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2 where a=10 and b=10;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 8 Using where
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2 DEPENDENT SUBQUERY t1 index_subquery idx idx 5 func 4 Using where; Full scan on NULL key
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Warnings:
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Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
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Note 1003 select `test`.`t2`.`oref` AS `oref`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`b`),<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on idx checking NULL where ((`test`.`t1`.`oref` = `test`.`t2`.`oref`) and trigcond(((<cache>(`test`.`t2`.`a`) = `test`.`t1`.`ie1`) or isnull(`test`.`t1`.`ie1`))) and trigcond(((<cache>(`test`.`t2`.`b`) = `test`.`t1`.`ie2`) or isnull(`test`.`t1`.`ie2`)))) having (trigcond(<is_not_null_test>(`test`.`t1`.`ie1`)) and trigcond(<is_not_null_test>(`test`.`t1`.`ie2`)))))) AS `Z` from `test`.`t2` where ((`test`.`t2`.`b` = 10) and (`test`.`t2`.`a` = 10))
|
|
drop table t1, t2;
|
|
create table t1 (oref char(4), grp int, ie int);
|
|
insert into t1 (oref, grp, ie) values
|
|
('aa', 10, 2),
|
|
('aa', 10, 1),
|
|
('aa', 20, NULL),
|
|
('bb', 10, 3),
|
|
('cc', 10, 4),
|
|
('cc', 20, NULL),
|
|
('ee', 10, NULL),
|
|
('ee', 10, NULL),
|
|
('ff', 20, 2),
|
|
('ff', 20, 1);
|
|
create table t2 (oref char(4), a int);
|
|
insert into t2 values
|
|
('ee', NULL),
|
|
('bb', 2),
|
|
('ff', 2),
|
|
('cc', 3),
|
|
('aa', 1),
|
|
('dd', NULL),
|
|
('bb', NULL);
|
|
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
|
|
oref a Z
|
|
ee NULL NULL
|
|
bb 2 0
|
|
ff 2 1
|
|
cc 3 NULL
|
|
aa 1 1
|
|
dd NULL 0
|
|
bb NULL NULL
|
|
select oref, a from t2 where a in (select ie from t1 where oref=t2.oref);
|
|
oref a
|
|
ff 2
|
|
aa 1
|
|
select oref, a from t2 where a not in (select ie from t1 where oref=t2.oref);
|
|
oref a
|
|
bb 2
|
|
dd NULL
|
|
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by grp) Z from t2;
|
|
oref a Z
|
|
ee NULL NULL
|
|
bb 2 0
|
|
ff 2 0
|
|
cc 3 NULL
|
|
aa 1 1
|
|
dd NULL 0
|
|
bb NULL NULL
|
|
select oref, a from t2 where
|
|
a in (select min(ie) from t1 where oref=t2.oref group by grp);
|
|
oref a
|
|
aa 1
|
|
select oref, a from t2 where
|
|
a not in (select min(ie) from t1 where oref=t2.oref group by grp);
|
|
oref a
|
|
bb 2
|
|
ff 2
|
|
dd NULL
|
|
update t1 set ie=3 where oref='ff' and ie=1;
|
|
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by
|
|
grp) Z from t2;
|
|
oref a Z
|
|
ee NULL NULL
|
|
bb 2 0
|
|
ff 2 1
|
|
cc 3 NULL
|
|
aa 1 1
|
|
dd NULL 0
|
|
bb NULL NULL
|
|
select oref, a from t2 where a in (select min(ie) from t1 where
|
|
oref=t2.oref group by grp);
|
|
oref a
|
|
ff 2
|
|
aa 1
|
|
select oref, a from t2 where a not in (select min(ie) from t1 where
|
|
oref=t2.oref group by grp);
|
|
oref a
|
|
bb 2
|
|
dd NULL
|
|
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by
|
|
grp having min(ie) > 1) Z from t2;
|
|
oref a Z
|
|
ee NULL 0
|
|
bb 2 0
|
|
ff 2 1
|
|
cc 3 0
|
|
aa 1 0
|
|
dd NULL 0
|
|
bb NULL NULL
|
|
select oref, a from t2 where a in (select min(ie) from t1 where
|
|
oref=t2.oref group by grp having min(ie) > 1);
|
|
oref a
|
|
ff 2
|
|
select oref, a from t2 where a not in (select min(ie) from t1 where
|
|
oref=t2.oref group by grp having min(ie) > 1);
|
|
oref a
|
|
ee NULL
|
|
bb 2
|
|
cc 3
|
|
aa 1
|
|
dd NULL
|
|
alter table t1 add index idx(ie);
|
|
explain select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
|
|
2 DEPENDENT SUBQUERY t1 index_subquery idx idx 5 func 4 Using where; Full scan on NULL key
|
|
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
|
|
oref a Z
|
|
ee NULL NULL
|
|
bb 2 0
|
|
ff 2 1
|
|
cc 3 NULL
|
|
aa 1 1
|
|
dd NULL 0
|
|
bb NULL NULL
|
|
select oref, a from t2 where a in (select ie from t1 where oref=t2.oref);
|
|
oref a
|
|
ff 2
|
|
aa 1
|
|
select oref, a from t2 where a not in (select ie from t1 where oref=t2.oref);
|
|
oref a
|
|
bb 2
|
|
dd NULL
|
|
alter table t1 drop index idx;
|
|
alter table t1 add index idx(oref,ie);
|
|
explain select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
|
|
2 DEPENDENT SUBQUERY t1 ref_or_null idx idx 10 test.t2.oref,func 4 Using where; Using index; Full scan on NULL key
|
|
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
|
|
oref a Z
|
|
ee NULL NULL
|
|
bb 2 0
|
|
ff 2 1
|
|
cc 3 NULL
|
|
aa 1 1
|
|
dd NULL 0
|
|
bb NULL NULL
|
|
select oref, a from t2 where a in (select ie from t1 where oref=t2.oref);
|
|
oref a
|
|
ff 2
|
|
aa 1
|
|
select oref, a from t2 where a not in (select ie from t1 where oref=t2.oref);
|
|
oref a
|
|
bb 2
|
|
dd NULL
|
|
explain
|
|
select oref, a,
|
|
a in (select min(ie) from t1 where oref=t2.oref
|
|
group by grp having min(ie) > 1) Z
|
|
from t2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
|
|
2 DEPENDENT SUBQUERY t1 ref idx idx 5 test.t2.oref 2 Using where; Using temporary; Using filesort
|
|
select oref, a,
|
|
a in (select min(ie) from t1 where oref=t2.oref
|
|
group by grp having min(ie) > 1) Z
|
|
from t2;
|
|
oref a Z
|
|
ee NULL 0
|
|
bb 2 0
|
|
ff 2 1
|
|
cc 3 0
|
|
aa 1 0
|
|
dd NULL 0
|
|
bb NULL NULL
|
|
select oref, a from t2 where a in (select min(ie) from t1 where oref=t2.oref
|
|
group by grp having min(ie) > 1);
|
|
oref a
|
|
ff 2
|
|
select oref, a from t2 where a not in (select min(ie) from t1 where oref=t2.oref
|
|
group by grp having min(ie) > 1);
|
|
oref a
|
|
ee NULL
|
|
bb 2
|
|
cc 3
|
|
aa 1
|
|
dd NULL
|
|
drop table t1,t2;
|
|
create table t1 (oref char(4), grp int, ie1 int, ie2 int);
|
|
insert into t1 (oref, grp, ie1, ie2) values
|
|
('aa', 10, 2, 1),
|
|
('aa', 10, 1, 1),
|
|
('aa', 20, 2, 1),
|
|
('bb', 10, 3, 1),
|
|
('cc', 10, 4, 2),
|
|
('cc', 20, 3, 2),
|
|
('ee', 10, 2, 1),
|
|
('ee', 10, 1, 2),
|
|
('ff', 20, 2, 2),
|
|
('ff', 20, 1, 2);
|
|
create table t2 (oref char(4), a int, b int);
|
|
insert into t2 values
|
|
('ee', NULL, 1),
|
|
('bb', 2, 1),
|
|
('ff', 2, 2),
|
|
('cc', 3, NULL),
|
|
('bb', NULL, NULL),
|
|
('aa', 1, 1),
|
|
('dd', 1, NULL);
|
|
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2;
|
|
oref a b Z
|
|
ee NULL 1 NULL
|
|
bb 2 1 0
|
|
ff 2 2 1
|
|
cc 3 NULL NULL
|
|
bb NULL NULL NULL
|
|
aa 1 1 1
|
|
dd 1 NULL 0
|
|
select oref, a, b from t2 where (a,b) in (select ie1,ie2 from t1 where oref=t2.oref);
|
|
oref a b
|
|
ff 2 2
|
|
aa 1 1
|
|
select oref, a, b from t2 where (a,b) not in (select ie1,ie2 from t1 where oref=t2.oref);
|
|
oref a b
|
|
bb 2 1
|
|
dd 1 NULL
|
|
select oref, a, b,
|
|
(a,b) in (select min(ie1),max(ie2) from t1
|
|
where oref=t2.oref group by grp) Z
|
|
from t2;
|
|
oref a b Z
|
|
ee NULL 1 0
|
|
bb 2 1 0
|
|
ff 2 2 0
|
|
cc 3 NULL NULL
|
|
bb NULL NULL NULL
|
|
aa 1 1 1
|
|
dd 1 NULL 0
|
|
select oref, a, b from t2 where
|
|
(a,b) in (select min(ie1), max(ie2) from t1 where oref=t2.oref group by grp);
|
|
oref a b
|
|
aa 1 1
|
|
select oref, a, b from t2 where
|
|
(a,b) not in (select min(ie1), max(ie2) from t1 where oref=t2.oref group by grp);
|
|
oref a b
|
|
ee NULL 1
|
|
bb 2 1
|
|
ff 2 2
|
|
dd 1 NULL
|
|
alter table t1 add index idx(ie1,ie2);
|
|
explain select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
|
|
2 DEPENDENT SUBQUERY t1 index_subquery idx idx 5 func 4 Using where; Full scan on NULL key
|
|
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2;
|
|
oref a b Z
|
|
ee NULL 1 NULL
|
|
bb 2 1 0
|
|
ff 2 2 1
|
|
cc 3 NULL NULL
|
|
bb NULL NULL NULL
|
|
aa 1 1 1
|
|
dd 1 NULL 0
|
|
select oref, a, b from t2 where (a,b) in (select ie1,ie2 from t1 where oref=t2.oref);
|
|
oref a b
|
|
ff 2 2
|
|
aa 1 1
|
|
select oref, a, b from t2 where (a,b) not in (select ie1,ie2 from t1 where oref=t2.oref);
|
|
oref a b
|
|
bb 2 1
|
|
dd 1 NULL
|
|
explain extended
|
|
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
|
|
2 DEPENDENT SUBQUERY t1 index_subquery idx idx 5 func 4 Using where; Full scan on NULL key
|
|
Warnings:
|
|
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
|
|
Note 1003 select `test`.`t2`.`oref` AS `oref`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`b`),<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on idx checking NULL where ((`test`.`t1`.`oref` = `test`.`t2`.`oref`) and trigcond(((<cache>(`test`.`t2`.`a`) = `test`.`t1`.`ie1`) or isnull(`test`.`t1`.`ie1`))) and trigcond(((<cache>(`test`.`t2`.`b`) = `test`.`t1`.`ie2`) or isnull(`test`.`t1`.`ie2`)))) having (trigcond(<is_not_null_test>(`test`.`t1`.`ie1`)) and trigcond(<is_not_null_test>(`test`.`t1`.`ie2`)))))) AS `Z` from `test`.`t2`
|
|
drop table t1,t2;
|
|
create table t1 (oref char(4), grp int, ie int primary key);
|
|
insert into t1 (oref, grp, ie) values
|
|
('aa', 10, 2),
|
|
('aa', 10, 1),
|
|
('bb', 10, 3),
|
|
('cc', 10, 4),
|
|
('cc', 20, 5),
|
|
('cc', 10, 6);
|
|
create table t2 (oref char(4), a int);
|
|
insert into t2 values
|
|
('ee', NULL),
|
|
('bb', 2),
|
|
('cc', 5),
|
|
('cc', 2),
|
|
('cc', NULL),
|
|
('aa', 1),
|
|
('bb', NULL);
|
|
explain select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
|
|
2 DEPENDENT SUBQUERY t1 unique_subquery PRIMARY PRIMARY 4 func 1 Using where; Full scan on NULL key
|
|
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
|
|
oref a Z
|
|
ee NULL 0
|
|
bb 2 0
|
|
cc 5 1
|
|
cc 2 0
|
|
cc NULL NULL
|
|
aa 1 1
|
|
bb NULL NULL
|
|
select oref, a from t2 where a in (select ie from t1 where oref=t2.oref);
|
|
oref a
|
|
cc 5
|
|
aa 1
|
|
select oref, a from t2 where a not in (select ie from t1 where oref=t2.oref);
|
|
oref a
|
|
ee NULL
|
|
bb 2
|
|
cc 2
|
|
explain
|
|
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by grp) Z from t2;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
|
|
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 6 Using where; Using temporary; Using filesort
|
|
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by grp) Z from t2;
|
|
oref a Z
|
|
ee NULL 0
|
|
bb 2 0
|
|
cc 5 1
|
|
cc 2 0
|
|
cc NULL NULL
|
|
aa 1 1
|
|
bb NULL NULL
|
|
drop table t1,t2;
|
|
create table t1 (a int, b int);
|
|
insert into t1 values (0,0), (2,2), (3,3);
|
|
create table t2 (a int, b int);
|
|
insert into t2 values (1,1), (3,3);
|
|
select a, b, (a,b) in (select a, min(b) from t2 group by a) Z from t1;
|
|
a b Z
|
|
0 0 0
|
|
2 2 0
|
|
3 3 1
|
|
insert into t2 values (NULL,4);
|
|
select a, b, (a,b) in (select a, min(b) from t2 group by a) Z from t1;
|
|
a b Z
|
|
0 0 0
|
|
2 2 0
|
|
3 3 1
|
|
drop table t1,t2;
|
|
CREATE TABLE t1 (a int, b INT, c CHAR(10) NOT NULL, PRIMARY KEY (a, b));
|
|
INSERT INTO t1 VALUES (1,1,'a'), (1,2,'b'), (1,3,'c'), (1,4,'d'), (1,5,'e'),
|
|
(2,1,'f'), (2,2,'g'), (2,3,'h'), (3,4,'i'),(3,3,'j'), (3,2,'k'), (3,1,'l'),
|
|
(1,9,'m');
|
|
CREATE TABLE t2 (a int, b INT, c CHAR(10) NOT NULL, PRIMARY KEY (a, b));
|
|
INSERT INTO t2 SELECT * FROM t1;
|
|
SELECT a, MAX(b), (SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b))
|
|
as test FROM t1 GROUP BY a;
|
|
a MAX(b) test
|
|
1 9 m
|
|
2 3 h
|
|
3 4 i
|
|
SELECT * FROM t1 GROUP by t1.a
|
|
HAVING (MAX(t1.b) > (SELECT MAX(t2.b) FROM t2 WHERE t2.c < t1.c
|
|
HAVING MAX(t2.b+t1.a) < 10));
|
|
a b c
|
|
SELECT a, AVG(b), (SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=AVG(t1.b))
|
|
AS test FROM t1 GROUP BY a;
|
|
a AVG(b) test
|
|
1 4.0000 NULL
|
|
2 2.0000 k
|
|
3 2.5000 NULL
|
|
SELECT a,b,c FROM t1 WHERE b in (9,3,4) ORDER BY b,c;
|
|
a b c
|
|
1 3 c
|
|
2 3 h
|
|
3 3 j
|
|
1 4 d
|
|
3 4 i
|
|
1 9 m
|
|
SELECT a, MAX(b),
|
|
(SELECT COUNT(DISTINCT t.c) FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b)
|
|
LIMIT 1)
|
|
as cnt,
|
|
(SELECT t.b FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b) LIMIT 1)
|
|
as t_b,
|
|
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b) LIMIT 1)
|
|
as t_b,
|
|
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b) ORDER BY t.c LIMIT 1)
|
|
as t_b
|
|
FROM t1 GROUP BY a;
|
|
a MAX(b) cnt t_b t_b t_b
|
|
1 9 1 9 m m
|
|
2 3 1 3 h h
|
|
3 4 1 4 i i
|
|
SELECT a, MAX(b),
|
|
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b) LIMIT 1) as test
|
|
FROM t1 GROUP BY a;
|
|
a MAX(b) test
|
|
1 9 m
|
|
2 3 h
|
|
3 4 i
|
|
DROP TABLE t1, t2;
|