mirror of
https://github.com/MariaDB/server.git
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221 lines
9.2 KiB
Text
221 lines
9.2 KiB
Text
drop table if exists t0, t1;
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create table t0 (a int) engine=myisam;
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insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);
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#
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# Tests for single-table DELETE
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#
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explain select * from t0 where a=3;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 8 Using where
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explain delete from t0 where a=3;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 8 Using where
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# DELETE without WHERE is a special case:
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explain delete from t0;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL 8 Deleting all rows
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create table t1 (a int, b int, filler char(100), key(a), key(b));
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insert into t1
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select A.a+10*B.a + 10*C.a, A.a+10*B.a + 10*C.a, 'filler'
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from t0 A, t0 B, t0 C;
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# This should use an index, possible_keys=NULL because there is no WHERE
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explain delete from t1 order by a limit 2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 index NULL a 5 NULL 2
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# This should use range, possible_keys={a,b}
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explain delete from t1 where a<20 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 SIMPLE t1 range a,b a 5 NULL 1 Using where
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# This should use ALL + filesort
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explain delete from t1 order by a+1 limit 2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 512 Using filesort
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# This should use range + using filesort
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explain delete from t1 where a<20 order by b limit 2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 range a a 5 NULL 1 Using where; Using filesort
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# Try some subqueries:
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explain delete from t1 where a < (select max(a) from t0);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 range a a 5 NULL 1 Using where
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2 SUBQUERY t0 ALL NULL NULL NULL NULL 8
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explain delete from t1 where a < (select max(a) from t0 where a < t1.b);
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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 512 Using where
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 8 Using where
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#
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# Tests for multi-table DELETE
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#
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explain delete t1 from t0, t1 where t0.a = t1.a;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 8 Using where
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1 SIMPLE t1 ref a a 5 test.t0.a 4
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drop table t0, t1;
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# ###################################################################
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# ## EXPLAIN UPDATE tests
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# ###################################################################
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create table t0 (a int) engine=myisam;
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insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);
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explain update t0 set a=3 where a=4;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 8 Using where
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create table t1 (a int, b int, filler char(100), key(a), key(b));
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insert into t1
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select A.a+10*B.a + 10*C.a, A.a+10*B.a + 10*C.a, 'filler'
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from t0 A, t0 B, t0 C;
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explain update t1 set a=a+1 where 3>4;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
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explain update t1 set a=a+1 where a=3 and a=4;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
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# This should use an index, possible_keys=NULL because there is no WHERE
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explain update t1 set a=a+1 order by a limit 2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 512 Using filesort
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# This should use range, possible_keys={a,b}
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explain update t1 set filler='fooo' where a<20 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 SIMPLE t1 range a,b a 5 NULL 1 Using where
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# This should use ALL + filesort
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explain update t1 set filler='fooo' order by a+1 limit 2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 ALL NULL NULL NULL NULL 512 Using filesort
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# This should use range + using filesort
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explain update t1 set filler='fooo' where a<20 order by b limit 2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 range a a 5 NULL 1 Using where; Using filesort
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# Try some subqueries:
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explain update t1 set filler='fooo' where a < (select max(a) from t0);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t1 range a a 5 NULL 1 Using where
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2 SUBQUERY t0 ALL NULL NULL NULL NULL 8
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explain update t1 set filler='fooo' where a < (select max(a) from t0 where a < t1.b);
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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 512 Using where
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 8 Using where
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#
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# Tests for multi-table UPDATE
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#
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explain update t0, t1 set t1.a=t1.a+1 where t0.a = t1.a;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 8 Using where
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1 SIMPLE t1 ref a a 5 test.t0.a 4
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drop table t0, t1;
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#
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# Try DELETE ... RETURNING ...
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#
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create table t0 (a int);
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insert into t0 values (1),(2),(3),(4);
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explain delete from t0 where a=1 returning a;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 4 Using where
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explain delete from t0 returning a;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 4
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drop table t0;
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#
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# MDEV-5070 - EXPLAIN INSERT ... SELECT crashes on 10.0-base-explain-slowquerylog
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#
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create table t0 (a int);
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insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);
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create table t1 (a int);
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explain insert into t1 select * from t0;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 8
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explain replace into t1 select * from t0;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t0 ALL NULL NULL NULL NULL 8
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drop table t0, t1;
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#
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# MDEV-5067: Valgrind warnings (Invalid read) in QPF_table_access::print_explain
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#
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CREATE TABLE t1 (i INT) ENGINE=MyISAM;
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INSERT INTO t1 VALUES (7),(0),(9);
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SELECT * FROM t1 INNER JOIN ( SELECT DISTINCT * FROM t1 ) AS sq ON (sq.i = t1.i);
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i i
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7 7
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0 0
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9 9
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DROP TABLE t1;
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#
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# MDEV-5093, MDEV-5094: EXPLAIN PARTITIONS and EXPLAIN EXTENDED do not
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# work for EXPLAIN UPDATE.
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#
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create table t1 (i int);
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explain partitions update t1 set i = 3;
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id select_type table partitions type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 NULL ALL NULL NULL NULL NULL 0
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create table t2 (a int, b int) partition by hash(a) partitions 5;
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insert into t2 values (0,0),(1,1),(2,2),(3,3),(4,4);
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explain partitions update t2 set b=3 where a in (3,4);
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id select_type table partitions type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 p3,p4 ALL NULL NULL NULL NULL 2 Using where
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explain partitions delete from t2 where a in (3,4);
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id select_type table partitions type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 p3,p4 ALL NULL NULL NULL NULL 2 Using where
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explain extended update t2 set b=3 where a in (3,4);
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 2 100.00 Using where
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explain extended delete from t2 where a in (3,4);
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 2 100.00 Using where
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drop table t1,t2;
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#
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# Check the special case where partition pruning removed all partitions
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#
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create table t1 (a int, b int)
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partition by range (a) (
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partition p0 values less than (10),
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partition p1 values less than (20),
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partition p2 values less than (30)
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);
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insert into t1 values (9,9), (19,19), (29,29);
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explain partitions select * from t1 where a in (32,33);
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id select_type table partitions type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
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explain partitions delete from t1 where a in (32,33);
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id select_type table partitions type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL No matching rows after partition pruning
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explain partitions update t1 set b=12345 where a in (32,33);
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id select_type table partitions type possible_keys key key_len ref rows Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL No matching rows after partition pruning
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drop table t1;
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#
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# Tests for EXPLAIN INSERT ... VALUES
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#
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create table t1 (a int, key(a));
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explain insert into t1 values (1),(2),(3);
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id select_type table type possible_keys key key_len ref rows Extra
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1 INSERT t1 ALL NULL NULL NULL NULL NULL NULL
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insert into t1 values (1),(2),(3);
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create table t2 (a int, b int);
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explain insert into t2 values
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(10, 1+(select max(a) from t1)),
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(11, 1+(select max(a+1) from t1));
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id select_type table type possible_keys key key_len ref rows Extra
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1 INSERT t2 ALL NULL NULL NULL NULL NULL NULL
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3 SUBQUERY t1 index NULL a 5 NULL 3 Using index
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2 SUBQUERY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
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drop table t1,t2;
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#
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# MDEV-5122: "Commands out of sync", "Malformed packet" or client hang up on unique key violation
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#
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drop table if exists t1;
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Warnings:
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Note 1051 Unknown table 'test.t1'
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drop function if exists f1;
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create table t1 (a int, unique(a));
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create function f1(x int)
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returns int
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begin
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insert into t1 values(x),(x);
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return 10;
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end|
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select f1(100);
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ERROR 23000: Duplicate entry '100' for key 'a'
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select 'OK';
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OK
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OK
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drop function f1;
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drop table t1;
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