mirror of
https://github.com/MariaDB/server.git
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2cfc450bf7
"Re-factor the code for post-join operations". The patch mainly contains the code ported from mysql-5.6 and created for two essential architectural changes: 1. WL#5558: Resolve ORDER BY execution method at the optimization stage 2. WL#6071: Inline tmp tables into the nested loops algorithm The first task was implemented for mysql-5.6 by Ole John Aske. It allows to make all decisions on ORDER BY operation at the optimization stage. The second task implemented for mysql-5.6 by Evgeny Potemkin adds JOIN_TAB nodes for post-join operations that require temporary tables. It allows to execute these operations within the nested loops algorithm that used to be used before this task only for join queries. Besides these task moves all planning on the execution of these operations from the execution phase to the optimization phase. Some other re-factoring changes of mysql-5.6 were pulled in, mainly because it was easier to pull them in than roll them back. In particular all changes concerning Ref_ptr_array were incorporated. The port required some changes in the MariaDB code that concerned the functionality of EXPLAIN and ANALYZE. This was done mainly by Sergey Petrunia.
1188 lines
44 KiB
Text
1188 lines
44 KiB
Text
drop table if exists t0, t1, t2, t3, t4;
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drop view if exists v1;
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SET @old_debug= @@session.debug;
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set debug_sync='RESET';
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create table t0 (a int);
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insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
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create table t1 (a int);
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insert into t1 select A.a + 10*B.a + 100*C.a from t0 A, t0 B, t0 C;
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alter table t1 add b int, add c int, add filler char(32);
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update t1 set b=a, c=a, filler='fooo';
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alter table t1 add key(a), add key(b);
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show explain for 2000000000;
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ERROR HY000: Unknown thread id: 2000000000
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show explain for (select max(a) from t0);
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ERROR HY000: You may only use constant expressions in this statement
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SET @old_debug= @@session.debug;
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show explain for $thr2;
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ERROR HY000: Target is not running an EXPLAINable command
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show explain for $thr1;
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ERROR HY000: Target is not running an EXPLAINable command
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set @show_explain_probe_select_id=1;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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select count(*) from t1 where a < 100000;
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show explain for $thr2;
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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 a a 5 NULL 1000 Using where; Using index
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Warnings:
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Note 1003 select count(*) from t1 where a < 100000
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count(*)
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1000
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select max(c) from t1 where a < 10;
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show explain for $thr2;
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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 10 Using index condition
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Warnings:
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Note 1003 select max(c) from t1 where a < 10
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max(c)
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9
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# We can catch EXPLAIN, too.
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set @show_expl_tmp= @@optimizer_switch;
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set optimizer_switch='index_condition_pushdown=on,mrr=on,mrr_sort_keys=on';
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explain select max(c) from t1 where a < 10;
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show explain for $thr2;
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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 10 Using index condition; Rowid-ordered scan
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Warnings:
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Note 1003 explain select max(c) from t1 where a < 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 a 5 NULL 10 Using index condition; Rowid-ordered scan
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set optimizer_switch= @show_expl_tmp;
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set debug_dbug=@old_debug;
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# UNION, first branch
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set @show_explain_probe_select_id=1;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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explain select a from t0 A union select a+1 from t0 B;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY A ALL NULL NULL NULL NULL 10
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2 UNION B ALL NULL NULL NULL NULL 10
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NULL UNION RESULT <union1,2> ALL NULL NULL NULL NULL NULL
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Warnings:
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Note 1003 explain select a from t0 A union select a+1 from t0 B
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY A ALL NULL NULL NULL NULL 10
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2 UNION B ALL NULL NULL NULL NULL 10
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NULL UNION RESULT <union1,2> ALL NULL NULL NULL NULL NULL
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set debug_dbug=@old_debug;
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# UNION, second branch
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set @show_explain_probe_select_id=1;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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explain select a from t0 A union select a+1 from t0 B;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY A ALL NULL NULL NULL NULL 10
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2 UNION B ALL NULL NULL NULL NULL 10
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NULL UNION RESULT <union1,2> ALL NULL NULL NULL NULL NULL
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Warnings:
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Note 1003 explain select a from t0 A union select a+1 from t0 B
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY A ALL NULL NULL NULL NULL 10
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2 UNION B ALL NULL NULL NULL NULL 10
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NULL UNION RESULT <union1,2> ALL NULL NULL NULL NULL NULL
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set debug_dbug=@old_debug;
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# Uncorrelated subquery, select
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set @show_explain_probe_select_id=1;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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select a, (select max(a) from t0 B) from t0 A where a<1;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY A ALL NULL NULL NULL NULL 10 Using where
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2 SUBQUERY B ALL NULL NULL NULL NULL 10
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Warnings:
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Note 1003 select a, (select max(a) from t0 B) from t0 A where a<1
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a (select max(a) from t0 B)
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0 9
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set debug_dbug=@old_debug;
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# Uncorrelated subquery, explain
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set @show_explain_probe_select_id=1;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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explain select a, (select max(a) from t0 B) from t0 A where a<1;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY A ALL NULL NULL NULL NULL 10 Using where
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2 SUBQUERY B ALL NULL NULL NULL NULL 10
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Warnings:
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Note 1003 explain select a, (select max(a) from t0 B) from t0 A where a<1
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY A ALL NULL NULL NULL NULL 10 Using where
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2 SUBQUERY B ALL NULL NULL NULL NULL 10
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set debug_dbug=@old_debug;
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# correlated subquery, select
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set @show_explain_probe_select_id=1;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY a ALL NULL NULL NULL NULL 10 Using where
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2 DEPENDENT SUBQUERY b ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1
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a (select max(a) from t0 b where b.a+a.a<10)
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0 9
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set debug_dbug=@old_debug;
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# correlated subquery, explain
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set @show_explain_probe_select_id=1;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY a ALL NULL NULL NULL NULL 10 Using where
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2 DEPENDENT SUBQUERY b ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1
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a (select max(a) from t0 b where b.a+a.a<10)
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0 9
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set debug_dbug=@old_debug;
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# correlated subquery, select, while inside the subquery
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set @show_explain_probe_select_id=2;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY a ALL NULL NULL NULL NULL 10 Using where
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2 DEPENDENT SUBQUERY b ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1
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a (select max(a) from t0 b where b.a+a.a<10)
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0 9
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set debug_dbug=@old_debug;
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# correlated subquery, explain, while inside the subquery
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set @show_explain_probe_select_id=2;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY a ALL NULL NULL NULL NULL 10 Using where
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2 DEPENDENT SUBQUERY b ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1
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a (select max(a) from t0 b where b.a+a.a<10)
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0 9
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set debug_dbug=@old_debug;
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# correlated subquery, explain, while inside the subquery
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set @show_explain_probe_select_id=1;
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set debug_dbug='+d,show_explain_probe_join_exec_end';
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select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1;
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show explain for $thr2;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY a ALL NULL NULL NULL NULL 10 Using where
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2 DEPENDENT SUBQUERY b ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 select a, (select max(a) from t0 b where b.a+a.a<10) from t0 a where a<1
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a (select max(a) from t0 b where b.a+a.a<10)
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0 9
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set debug_dbug=@old_debug;
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# Try to do SHOW EXPLAIN for a query that runs a SET command:
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# I've found experimentally that select_id==2 here...
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#
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set @show_explain_probe_select_id=2;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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set @foo= (select max(a) from t0 where sin(a) >0);
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show explain for $thr2;
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ERROR HY000: Target is not running an EXPLAINable command
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kill query $thr2;
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ERROR 70100: Query execution was interrupted
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set debug_dbug=@old_debug;
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#
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# Attempt SHOW EXPLAIN for an UPDATE
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#
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create table t2 as select a as a, a as dummy from t0 limit 2;
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set @show_explain_probe_select_id=2;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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update t2 set dummy=0 where (select max(a) from t0 where t2.a + t0.a <3) >3 ;
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show explain for $thr2;
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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 Using where
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 update t2 set dummy=0 where (select max(a) from t0 where t2.a + t0.a <3) >3
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show explain for $thr2;
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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 Using where
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 update t2 set dummy=0 where (select max(a) from t0 where t2.a + t0.a <3) >3
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drop table t2;
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set debug_dbug=@old_debug;
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#
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# Attempt SHOW EXPLAIN for a DELETE (UPD: now works)
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#
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create table t2 as select a as a, a as dummy from t0 limit 2;
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set @show_explain_probe_select_id=2;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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delete from t2 where (select max(a) from t0 where t2.a + t0.a <3) >3 ;
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show explain for $thr2;
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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 Using where
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 delete from t2 where (select max(a) from t0 where t2.a + t0.a <3) >3
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show explain for $thr2;
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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 Using where
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 delete from t2 where (select max(a) from t0 where t2.a + t0.a <3) >3
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drop table t2;
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set debug_dbug=@old_debug;
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#
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# Multiple SHOW EXPLAIN calls for one select
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#
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create table t2 as select a as a, a as dummy from t0 limit 3;
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set @show_explain_probe_select_id=2;
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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select t2.a, ((select max(a) from t0 where t2.a + t0.a <3) >3) as SUBQ from t2;
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show explain for $thr2;
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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 3
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 select t2.a, ((select max(a) from t0 where t2.a + t0.a <3) >3) as SUBQ from t2
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show explain for $thr2;
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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 3
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 select t2.a, ((select max(a) from t0 where t2.a + t0.a <3) >3) as SUBQ from t2
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show explain for $thr2;
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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 3
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2 DEPENDENT SUBQUERY t0 ALL NULL NULL NULL NULL 10 Using where
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Warnings:
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Note 1003 select t2.a, ((select max(a) from t0 where t2.a + t0.a <3) >3) as SUBQ from t2
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a SUBQ
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0 0
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1 0
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2 0
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drop table t2;
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set debug_dbug=@old_debug;
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#
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# SHOW EXPLAIN for SELECT ... ORDER BY with "Using filesort"
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#
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explain select * from t0 order by 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 10 Using filesort
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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set @show_explain_probe_select_id=1;
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select * from t0 order by a;
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show explain for $thr2;
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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 10 Using filesort
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Warnings:
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Note 1003 select * from t0 order by a
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a
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0
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1
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2
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3
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4
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5
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6
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7
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8
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9
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set debug_dbug=@old_debug;
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#
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# SHOW EXPLAIN for SELECT ... with "Using temporary"
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#
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explain select distinct 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 SIMPLE t0 ALL NULL NULL NULL NULL 10 Using temporary
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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set @show_explain_probe_select_id=1;
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select distinct a from t0;
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show explain for $thr2;
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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 10 Using temporary
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Warnings:
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Note 1003 select distinct a from t0
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a
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0
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1
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2
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3
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4
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5
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6
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7
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8
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9
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set debug_dbug=@old_debug;
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#
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# SHOW EXPLAIN for SELECT ... with "Using temporary; Using filesort"
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#
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explain select distinct 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 SIMPLE t0 ALL NULL NULL NULL NULL 10 Using temporary
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set debug_dbug='+d,show_explain_probe_join_exec_start';
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set @show_explain_probe_select_id=1;
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select distinct a from t0;
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show explain for $thr2;
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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 10 Using temporary
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Warnings:
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Note 1003 select distinct a from t0
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a
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0
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1
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2
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3
|
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4
|
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5
|
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6
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7
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8
|
||
9
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set debug_dbug=@old_debug;
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#
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# MDEV-238: SHOW EXPLAIN: Server crashes in JOIN::print_explain with FROM subquery and GROUP BY
|
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#
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CREATE TABLE t2 ( a INT );
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INSERT INTO t2 VALUES (1),(2),(1),(4),(2);
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explain SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t2 ALL NULL NULL NULL NULL 5 Using temporary; Using filesort
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1 SIMPLE t2 ALL NULL NULL NULL NULL 5 Using join buffer (flat, BNL join)
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set debug_dbug='+d,show_explain_in_find_all_keys';
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SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a;
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# FIXED by "conservative assumptions about when QEP is available" fix:
|
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# NOTE: current code will not show "Using join buffer":
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show explain for $thr2;
|
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id select_type table type possible_keys key key_len ref rows Extra
|
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1 SIMPLE t2 ALL NULL NULL NULL NULL 5 Using temporary; Using filesort
|
||
1 SIMPLE t2 ALL NULL NULL NULL NULL 5 Using join buffer (flat, BNL join)
|
||
Warnings:
|
||
Note 1003 SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a
|
||
a
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1
|
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2
|
||
4
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set debug_dbug=@old_debug;
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DROP TABLE t2;
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#
|
||
# MDEV-239: Assertion `field_types == 0 ... ' failed in Protocol_text::store(double, uint32, String*) with
|
||
# SHOW EXPLAIN over EXPLAIN EXTENDED
|
||
#
|
||
CREATE TABLE t2 (a INT);
|
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INSERT INTO t2 VALUES (1),(2),(1),(4),(2);
|
||
EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a ;
|
||
id select_type table type possible_keys key key_len ref rows filtered Extra
|
||
1 SIMPLE t2 ALL NULL NULL NULL NULL 5 100.00 Using temporary; Using filesort
|
||
1 SIMPLE t2 ALL NULL NULL NULL NULL 5 100.00 Using join buffer (flat, BNL join)
|
||
Warnings:
|
||
Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` join `test`.`t2` group by `test`.`t2`.`a`
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_end';
|
||
EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a ;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t2 ALL NULL NULL NULL NULL 5 Using temporary; Using filesort
|
||
1 SIMPLE t2 ALL NULL NULL NULL NULL 5 Using join buffer (flat, BNL join)
|
||
Warnings:
|
||
Note 1003 EXPLAIN EXTENDED SELECT alias.a FROM t2, ( SELECT * FROM t2 ) AS alias GROUP BY alias.a
|
||
id select_type table type possible_keys key key_len ref rows filtered Extra
|
||
1 SIMPLE t2 ALL NULL NULL NULL NULL 5 100.00 Using temporary; Using filesort
|
||
1 SIMPLE t2 ALL NULL NULL NULL NULL 5 100.00 Using join buffer (flat, BNL join)
|
||
Warnings:
|
||
Note 1003 select `test`.`t2`.`a` AS `a` from `test`.`t2` join `test`.`t2` group by `test`.`t2`.`a`
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t2;
|
||
#
|
||
# MDEV-240: SHOW EXPLAIN: Assertion `this->optimized == 2' failed in
|
||
# JOIN::print_explain on query with a JOIN, TEMPTABLE view,
|
||
#
|
||
CREATE TABLE t3 (a INT);
|
||
CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t3;
|
||
INSERT INTO t3 VALUES (8);
|
||
CREATE TABLE t2 (b INT);
|
||
INSERT INTO t2 VALUES (4),(5),(6),(7),(8),(9);
|
||
explain SELECT * FROM v1, t2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY <derived2> system NULL NULL NULL NULL 1
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 6
|
||
2 DERIVED t3 system NULL NULL NULL NULL 1
|
||
set @show_explain_probe_select_id=2;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_end';
|
||
SELECT * FROM v1, t2;
|
||
show explain for $thr2;
|
||
ERROR HY000: Target is not running an EXPLAINable command
|
||
kill query $thr2;
|
||
ERROR 70100: Query execution was interrupted
|
||
set debug_dbug=@old_debug;
|
||
DROP VIEW v1;
|
||
DROP TABLE t2, t3;
|
||
#
|
||
# MDEV-267: SHOW EXPLAIN: Server crashes in JOIN::print_explain on most of queries
|
||
#
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_end';
|
||
select sleep(1);
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL No tables used
|
||
Warnings:
|
||
Note 1003 select sleep(1)
|
||
sleep(1)
|
||
0
|
||
set debug_dbug=@old_debug;
|
||
#
|
||
# Same as above, but try another reason for JOIN to be degenerate
|
||
#
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_end';
|
||
select * from t0 where 1>10;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
|
||
Warnings:
|
||
Note 1003 select * from t0 where 1>10
|
||
a
|
||
set debug_dbug=@old_debug;
|
||
#
|
||
# Same as above, but try another reason for JOIN to be degenerate (2)
|
||
#
|
||
create table t3(a int primary key);
|
||
insert into t3 select a from t0;
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_end';
|
||
select * from t0,t3 where t3.a=112233;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL no matching row in const table
|
||
Warnings:
|
||
Note 1003 select * from t0,t3 where t3.a=112233
|
||
a a
|
||
set debug_dbug=@old_debug;
|
||
drop table t3;
|
||
#
|
||
# MDEV-270: SHOW EXPLAIN: server crashes in JOIN::print_explain on a query with
|
||
# select tables optimized away
|
||
#
|
||
CREATE TABLE t2 (pk INT PRIMARY KEY, a INT ) ENGINE=MyISAM;
|
||
INSERT INTO t2 VALUES
|
||
(1,4),(2,62),(3,7),(4,1),(5,0),(6,7),(7,7),(8,1),(9,7),(10,1),
|
||
(11,5),(12,2),(13,0),(14,1),(15,8),(16,1),(17,1),(18,9),(19,1),(20,5) ;
|
||
explain SELECT * FROM t2 WHERE a =
|
||
(SELECT MAX(a) FROM t2
|
||
WHERE pk= (SELECT MAX(pk) FROM t2 WHERE pk = 3)
|
||
);
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 20 Using where
|
||
2 SUBQUERY t2 const PRIMARY PRIMARY 4 const 1
|
||
3 SUBQUERY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_do_select';
|
||
SELECT * FROM t2 WHERE a =
|
||
(SELECT MAX(a) FROM t2
|
||
WHERE pk= (SELECT MAX(pk) FROM t2 WHERE pk = 3)
|
||
);
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 20 Using where
|
||
2 SUBQUERY t2 const PRIMARY PRIMARY 4 const 1
|
||
3 SUBQUERY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
|
||
Warnings:
|
||
Note 1003 SELECT * FROM t2 WHERE a =
|
||
(SELECT MAX(a) FROM t2
|
||
WHERE pk= (SELECT MAX(pk) FROM t2 WHERE pk = 3)
|
||
)
|
||
pk a
|
||
3 7
|
||
6 7
|
||
7 7
|
||
9 7
|
||
set debug_dbug=@old_debug;
|
||
drop table t2;
|
||
#
|
||
# MDEV-273: SHOW EXPLAIN: server crashes in JOIN::print_explain on a query with impossible WHERE
|
||
#
|
||
CREATE TABLE t2 (a1 INT, KEY(a1)) ENGINE=MyISAM;
|
||
INSERT INTO t2 VALUES
|
||
(4),(6),(7),(1),(0),(7),(7),(1),(7),(1),
|
||
(5),(2),(0),(1),(8),(1),(1),(9),(1),(5);
|
||
CREATE TABLE t3 (b1 INT) ENGINE=MyISAM;
|
||
INSERT INTO t3 VALUES
|
||
(4),(5),(8),(4),(8),(2),(9),(6),(4),(8),
|
||
(3),(5),(9),(6),(8),(3),(2),(6),(3),(1),
|
||
(4),(3),(1),(7),(0),(0),(9),(5),(9),(0),
|
||
(2),(2),(5),(9),(1),(4),(8),(6),(5),(5),
|
||
(1),(7),(2),(8),(9),(3),(2),(6),(6),(5),
|
||
(4),(3),(2),(7),(4),(6),(0),(8),(5),(8),
|
||
(2),(9),(7),(5),(7),(0),(4),(3),(1),(0),
|
||
(6),(2),(8),(3),(7),(3),(5),(5),(1),(2),
|
||
(1),(7),(1),(9),(9),(8),(3);
|
||
CREATE TABLE t4 (c1 INT) ENGINE=MyISAM;
|
||
EXPLAIN
|
||
SELECT count(*) FROM t2, t3
|
||
WHERE a1 < ALL (
|
||
SELECT a1 FROM t2
|
||
WHERE a1 IN ( SELECT a1 FROM t2, t4 )
|
||
);
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t2 index NULL a1 5 NULL 20 Using where; Using index
|
||
1 PRIMARY t3 ALL NULL NULL NULL NULL 87 Using join buffer (flat, BNL join)
|
||
2 SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_do_select';
|
||
SELECT count(*) FROM t2, t3
|
||
WHERE a1 < ALL (
|
||
SELECT a1 FROM t2
|
||
WHERE a1 IN ( SELECT a1 FROM t2, t4 )
|
||
);
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t2 index NULL a1 5 NULL 20 Using where; Using index
|
||
1 PRIMARY t3 ALL NULL NULL NULL NULL 87 Using join buffer (flat, BNL join)
|
||
2 SUBQUERY NULL NULL NULL NULL NULL NULL NULL no matching row in const table
|
||
Warnings:
|
||
Note 1003 SELECT count(*) FROM t2, t3
|
||
WHERE a1 < ALL (
|
||
SELECT a1 FROM t2
|
||
WHERE a1 IN ( SELECT a1 FROM t2, t4 )
|
||
)
|
||
count(*)
|
||
1740
|
||
set debug_dbug=@old_debug;
|
||
drop table t2, t3, t4;
|
||
#
|
||
# MDEV-275: SHOW EXPLAIN: server crashes in JOIN::print_explain with IN subquery and aggregate function
|
||
#
|
||
CREATE TABLE t2 ( `pk` INT NOT NULL PRIMARY KEY, `a1` INT NOT NULL, KEY(`a1`)) ENGINE=MyISAM;
|
||
INSERT INTO t2 VALUES
|
||
(1,5),(2,4),(3,6),(4,9),(5,2),(6,8),(7,4),(8,8),(9,0),(10,43),
|
||
(11,23),(12,3),(13,45),(14,16),(15,2),(16,33),(17,2),(18,5),(19,9),(20,2);
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_end';
|
||
SELECT * FROM t2 WHERE (5, 78) IN (SELECT `a1`, MAX(`a1`) FROM t2 GROUP BY `a1`);
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY <subquery2> const distinct_key distinct_key 8 const,const 1
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 20 Using join buffer (flat, BNL join)
|
||
2 MATERIALIZED t2 index NULL a1 4 NULL 20 Using index
|
||
Warnings:
|
||
Note 1003 SELECT * FROM t2 WHERE (5, 78) IN (SELECT `a1`, MAX(`a1`) FROM t2 GROUP BY `a1`)
|
||
pk a1
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t2;
|
||
DROP TABLE t1;
|
||
#
|
||
# MDEV-305: SHOW EXPLAIN: ref returned by SHOW EXPLAIN is different from the normal EXPLAIN ('const' vs empty string)
|
||
#
|
||
CREATE TABLE t1(a INT, KEY(a));
|
||
INSERT INTO t1 VALUES (3),(1),(5),(1);
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
SELECT 'test' FROM t1 WHERE a=1;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t1 ref a a 5 const 1 Using index
|
||
Warnings:
|
||
Note 1003 SELECT 'test' FROM t1 WHERE a=1
|
||
test
|
||
test
|
||
test
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t1;
|
||
#
|
||
# MDEV-299: SHOW EXPLAIN: Plan produced by SHOW EXPLAIN changes back and forth during query execution
|
||
#
|
||
create table t1 (key1 int, col1 int, col2 int, filler char(100), key(key1));
|
||
insert into t1 select A.a+ 10 * B.a, 10, 10, 'filler-data' from t0 A, t0 B;
|
||
update t1 set col1=3, col2=10 where key1=1;
|
||
update t1 set col1=3, col2=1000 where key1=2;
|
||
update t1 set col1=3, col2=10 where key1=3;
|
||
update t1 set col1=3, col2=1000 where key1=4;
|
||
set @tmp_mdev299_jcl= @@join_cache_level;
|
||
set join_cache_level=0;
|
||
explain select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE A ALL NULL NULL NULL NULL 100 Using where
|
||
1 SIMPLE B ALL key1 NULL NULL NULL 100 Range checked for each record (index map: 0x1)
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_test_if_quick_select';
|
||
select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE A ALL NULL NULL NULL NULL 100 Using where
|
||
1 SIMPLE B ALL key1 NULL NULL NULL 100 Range checked for each record (index map: 0x1)
|
||
Warnings:
|
||
Note 1003 select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE A ALL NULL NULL NULL NULL 100 Using where
|
||
1 SIMPLE B ALL key1 NULL NULL NULL 100 Range checked for each record (index map: 0x1)
|
||
Warnings:
|
||
Note 1003 select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE A ALL NULL NULL NULL NULL 100 Using where
|
||
1 SIMPLE B ALL key1 NULL NULL NULL 100 Range checked for each record (index map: 0x1)
|
||
Warnings:
|
||
Note 1003 select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE A ALL NULL NULL NULL NULL 100 Using where
|
||
1 SIMPLE B ALL key1 NULL NULL NULL 100 Range checked for each record (index map: 0x1)
|
||
Warnings:
|
||
Note 1003 select count(*) from t1 A, t1 B where B.key1 < A.col2 and A.col1=3 AND B.col2 + 1 < 100
|
||
count(*)
|
||
212
|
||
set debug_dbug=@old_debug;
|
||
drop table t1;
|
||
#
|
||
# MDEV-297: SHOW EXPLAIN: Server gets stuck until timeout occurs while
|
||
# executing SHOW INDEX and SHOW EXPLAIN in parallel
|
||
#
|
||
CREATE TABLE t1(a INT, b INT, c INT, KEY(a), KEY(b), KEY(c));
|
||
INSERT INTO t1 (a) VALUES (3),(1),(5),(1);
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
SHOW INDEX FROM t1;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE STATISTICS ALL NULL TABLE_SCHEMA,TABLE_NAME NULL NULL NULL Open_full_table; Scanned 0 databases
|
||
Warnings:
|
||
Note 1003 SHOW INDEX FROM t1
|
||
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
|
||
t1 1 a 1 a A NULL NULL NULL YES BTREE
|
||
t1 1 b 1 b A NULL NULL NULL YES BTREE
|
||
t1 1 c 1 c A NULL NULL NULL YES BTREE
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t1;
|
||
#
|
||
# MDEV-324: SHOW EXPLAIN: Plan produced by SHOW EXPLAIN for a query with TEMPTABLE view
|
||
# loses 'DERIVED' line on the way without saying that the plan was already deleted
|
||
#
|
||
CREATE TABLE t1 (a INT);
|
||
INSERT INTO t1 VALUES (1),(2);
|
||
CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t1;
|
||
EXPLAIN SELECT a + 1 FROM v1;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
|
||
2 DERIVED t1 ALL NULL NULL NULL NULL 2
|
||
set debug_dbug='+d,show_explain_probe_join_tab_preread';
|
||
set @show_explain_probe_select_id=1;
|
||
SELECT a + 1 FROM v1;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
|
||
2 DERIVED t1 ALL NULL NULL NULL NULL 2
|
||
Warnings:
|
||
Note 1003 SELECT a + 1 FROM v1
|
||
a + 1
|
||
2
|
||
3
|
||
set debug_dbug=@old_debug;
|
||
DROP VIEW v1;
|
||
DROP TABLE t1;
|
||
#
|
||
# MDEV-323: SHOW EXPLAIN: Plan produced by SHOW EXPLAIN loses
|
||
# 'UNION RESULT' line on the way without saying that the plan was already deleted
|
||
#
|
||
CREATE TABLE t1 (a INT);
|
||
INSERT INTO t1 VALUES (4),(6);
|
||
EXPLAIN
|
||
SELECT a FROM t1 WHERE a IN ( SELECT 1+SLEEP(0.01) UNION SELECT 2 );
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where
|
||
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL No tables used
|
||
3 DEPENDENT UNION NULL NULL NULL NULL NULL NULL NULL No tables used
|
||
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
|
||
set debug_dbug='+d,show_explain_probe_union_read';
|
||
SELECT a FROM t1 WHERE a IN ( SELECT 1+SLEEP(0.01) UNION SELECT 2 );
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where
|
||
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL No tables used
|
||
3 DEPENDENT UNION NULL NULL NULL NULL NULL NULL NULL No tables used
|
||
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
|
||
Warnings:
|
||
Note 1003 SELECT a FROM t1 WHERE a IN ( SELECT 1+SLEEP(0.01) UNION SELECT 2 )
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where
|
||
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL No tables used
|
||
3 DEPENDENT UNION NULL NULL NULL NULL NULL NULL NULL No tables used
|
||
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
|
||
Warnings:
|
||
Note 1003 SELECT a FROM t1 WHERE a IN ( SELECT 1+SLEEP(0.01) UNION SELECT 2 )
|
||
a
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t1;
|
||
#
|
||
# MDEV-327: SHOW EXPLAIN: Different select_type in plans produced by SHOW EXPLAIN
|
||
# and standard EXPLAIN: 'SUBQUERY' vs 'DEPENDENT SUBQUERY'
|
||
#
|
||
CREATE TABLE t1 (a INT) ENGINE=Aria;
|
||
INSERT INTO t1 VALUES
|
||
(4),(6),(3),(5),(3),(246),(2),(9),(3),(8),
|
||
(1),(8),(8),(5),(7),(5),(1),(6),(2),(9);
|
||
CREATE TABLE t2 (b INT) ENGINE=Aria;
|
||
INSERT INTO t2 VALUES
|
||
(1),(7),(4),(7),(0),(2),(9),(4),(0),(9),
|
||
(1),(3),(8),(8),(18),(84),(6),(3),(6),(6);
|
||
EXPLAIN
|
||
SELECT * FROM t1, ( SELECT * FROM t2 ) AS alias
|
||
WHERE a < ALL ( SELECT b FROM t1, t2 WHERE a = b );
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 ALL NULL NULL NULL NULL 20 Using where
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 20
|
||
3 SUBQUERY t1 ALL NULL NULL NULL NULL 20
|
||
3 SUBQUERY t2 ALL NULL NULL NULL NULL 20 Using where
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
SELECT * FROM t1, ( SELECT * FROM t2 ) AS alias
|
||
WHERE a < ALL ( SELECT b FROM t1, t2 WHERE a = b );
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 ALL NULL NULL NULL NULL 20 Using where
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 20
|
||
3 SUBQUERY t1 ALL NULL NULL NULL NULL 20
|
||
3 SUBQUERY t2 ALL NULL NULL NULL NULL 20 Using where
|
||
Warnings:
|
||
Note 1003 SELECT * FROM t1, ( SELECT * FROM t2 ) AS alias
|
||
WHERE a < ALL ( SELECT b FROM t1, t2 WHERE a = b )
|
||
a b
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t1, t2;
|
||
#
|
||
# Test that SHOW EXPLAIN will print 'Distinct'.
|
||
#
|
||
CREATE TABLE t1 (a int(10) unsigned not null primary key,b int(10) unsigned);
|
||
INSERT INTO t1 VALUES (1,1),(2,1),(3,1),(4,1);
|
||
CREATE TABLE t3 (a int(10) unsigned, key(A), b text);
|
||
INSERT INTO t3 VALUES (1,'1'),(2,'2');
|
||
create temporary table t4 select * from t3;
|
||
insert into t3 select * from t4;
|
||
insert into t4 select * from t3;
|
||
insert into t3 select * from t4;
|
||
insert into t4 select * from t3;
|
||
insert into t3 select * from t4;
|
||
insert into t4 select * from t3;
|
||
insert into t3 select * from t4;
|
||
explain select distinct t1.a from t1,t3 where t1.a=t3.a;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t1 index PRIMARY PRIMARY 4 NULL 4 Using index; Using temporary
|
||
1 SIMPLE t3 ref a a 5 test.t1.a 7 Using index; Distinct
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
select distinct t1.a from t1,t3 where t1.a=t3.a;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t1 index PRIMARY PRIMARY 4 NULL 4 Using index; Using temporary
|
||
1 SIMPLE t3 ref a a 5 test.t1.a 7 Using index; Distinct
|
||
Warnings:
|
||
Note 1003 select distinct t1.a from t1,t3 where t1.a=t3.a
|
||
a
|
||
1
|
||
2
|
||
set debug_dbug=@old_debug;
|
||
drop table t1,t3,t4;
|
||
#
|
||
# ---------- SHOW EXPLAIN and permissions -----------------
|
||
#
|
||
create user test2@localhost;
|
||
grant ALL on test.* to test2@localhost;
|
||
grant super on *.* to test2@localhost;
|
||
#
|
||
# First, make sure that user 'test2' cannot do SHOW EXPLAIN on us
|
||
#
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
select * from t0 where a < 3;
|
||
show explain for $thr2;
|
||
ERROR 42000: Access denied; you need (at least one of) the PROCESS privilege(s) for this operation
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t0 ALL NULL NULL NULL NULL 10 Using where
|
||
Warnings:
|
||
Note 1003 select * from t0 where a < 3
|
||
a
|
||
0
|
||
1
|
||
2
|
||
set debug_dbug=@old_debug;
|
||
#
|
||
# Check that user test2 can do SHOW EXPLAIN on its own queries
|
||
#
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
select * from t0 where a < 3;
|
||
show explain for $thr_con2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t0 ALL NULL NULL NULL NULL 10 Using where
|
||
Warnings:
|
||
Note 1003 select * from t0 where a < 3
|
||
a
|
||
0
|
||
1
|
||
2
|
||
#
|
||
# Now, grant test2 a PROCESSLIST permission, and see that he's able to observe us
|
||
#
|
||
grant process on *.* to test2@localhost;
|
||
set debug_dbug=@old_debug;
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
select * from t0 where a < 3;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t0 ALL NULL NULL NULL NULL 10 Using where
|
||
Warnings:
|
||
Note 1003 select * from t0 where a < 3
|
||
a
|
||
0
|
||
1
|
||
2
|
||
set debug_dbug=@old_debug;
|
||
revoke all privileges on test.* from test2@localhost;
|
||
drop user test2@localhost;
|
||
#
|
||
# Test that it is possible to KILL a SHOW EXPLAIN command that's waiting
|
||
# on its target thread
|
||
#
|
||
create table t1 (pk int primary key, data char(64)) engine=innodb;
|
||
insert into t1 select A.a + 10 * B.a + 100 * C.a, 'data1' from t0 A, t0 B, t0 C;
|
||
# Lock two threads
|
||
set autocommit=0;
|
||
select * from t1 where pk between 10 and 20 for update;
|
||
pk data
|
||
10 data1
|
||
11 data1
|
||
12 data1
|
||
13 data1
|
||
14 data1
|
||
15 data1
|
||
16 data1
|
||
17 data1
|
||
18 data1
|
||
19 data1
|
||
20 data1
|
||
set autocommit=0;
|
||
select * from t1 where pk between 10 and 20 for update;
|
||
# do: send_eval show explain for thr2;
|
||
kill query $thr_default;
|
||
ERROR 70100: Query execution was interrupted
|
||
rollback;
|
||
pk data
|
||
10 data1
|
||
11 data1
|
||
12 data1
|
||
13 data1
|
||
14 data1
|
||
15 data1
|
||
16 data1
|
||
17 data1
|
||
18 data1
|
||
19 data1
|
||
20 data1
|
||
drop table t1;
|
||
#
|
||
# Check that the I_S table is invisible
|
||
#
|
||
select table_name from information_schema.tables where table_schema='information_schema' and table_name like '%explain%';
|
||
table_name
|
||
#
|
||
# MDEV-325: SHOW EXPLAIN: Plan produced by SHOW EXPLAIN is different from standard EXPLAIN: type ALL vs 'index_merge'..
|
||
#
|
||
CREATE TABLE t1 (a INT, b INT, KEY(a), KEY(b)) ENGINE=MyISAM;
|
||
INSERT INTO t1 VALUES
|
||
(8,0),(128,5050),(5372,8),(234,7596),(2,0),(2907,8930),(1,0),
|
||
(0,5224),(8,7638),(960,5),(9872,1534),(0,2295),(3408,9809),
|
||
(7,0),(1168,0),(2089,5570),(0,205),(88,1018),(0,26528),
|
||
(0,0),(4,5567),(1444,145),(6,0),(1,7535),(7793,534),(70,9),
|
||
(178,1),(44,5),(189,0),(3,0);
|
||
EXPLAIN
|
||
SELECT a+SLEEP(0.01) FROM t1
|
||
WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129
|
||
ORDER BY b;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t1 index_merge a,b a,b 5,5 NULL 8 Using sort_union(a,b); Using where; Using filesort
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
SELECT a+SLEEP(0.01) FROM t1
|
||
WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129
|
||
ORDER BY b;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t1 index_merge a,b a,b 5,5 NULL 8 Using sort_union(a,b); Using where; Using filesort
|
||
Warnings:
|
||
Note 1003 SELECT a+SLEEP(0.01) FROM t1
|
||
WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129
|
||
ORDER BY b
|
||
a+SLEEP(0.01)
|
||
0
|
||
5372
|
||
70
|
||
0
|
||
0
|
||
0
|
||
0
|
||
set debug_dbug=@old_debug;
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_do_select';
|
||
SELECT a+SLEEP(0.01) FROM t1
|
||
WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129
|
||
ORDER BY b;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t1 index_merge a,b a,b 5,5 NULL 8 Using sort_union(a,b); Using where; Using filesort
|
||
Warnings:
|
||
Note 1003 SELECT a+SLEEP(0.01) FROM t1
|
||
WHERE a IN ( 255, 0 ) OR b BETWEEN 6 AND 129
|
||
ORDER BY b
|
||
a+SLEEP(0.01)
|
||
0
|
||
5372
|
||
70
|
||
0
|
||
0
|
||
0
|
||
0
|
||
set debug_dbug=@old_debug;
|
||
drop table t1;
|
||
#
|
||
# MDEV-298: SHOW EXPLAIN: Plan returned by SHOW EXPLAIN only contains
|
||
# 'Using temporary' while the standard EXPLAIN says 'Using temporary; Using filesort'
|
||
#
|
||
CREATE TABLE t1 (a INT);
|
||
INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),
|
||
(10),(11),(12),(13),(14),(15),(16);
|
||
INSERT INTO t1 SELECT t11.a FROM t1 t11, t1 t12, t1 t13;
|
||
EXPLAIN SELECT a FROM t1 GROUP BY a;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t1 ALL NULL NULL NULL NULL 4112 Using temporary; Using filesort
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
SELECT a FROM t1 GROUP BY a;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t1 ALL NULL NULL NULL NULL 4112 Using temporary; Using filesort
|
||
Warnings:
|
||
Note 1003 SELECT a FROM t1 GROUP BY a
|
||
a
|
||
1
|
||
2
|
||
3
|
||
4
|
||
5
|
||
6
|
||
7
|
||
8
|
||
9
|
||
10
|
||
11
|
||
12
|
||
13
|
||
14
|
||
15
|
||
16
|
||
set debug_dbug=@old_debug;
|
||
drop table t1;
|
||
#
|
||
# MDEV-408: SHOW EXPLAIN: Some values are chopped off in SHOW EXPLAIN output
|
||
#
|
||
CREATE TABLE t1 (a INT, b VARCHAR(35)) ENGINE=InnoDB;
|
||
INSERT INTO t1 VALUES (3989,'Abilene'),(3873,'Akron');
|
||
CREATE TABLE t2 (c INT, d VARCHAR(52) PRIMARY KEY, KEY(c)) ENGINE=InnoDB;
|
||
INSERT INTO t2 VALUES (86,'English'),(87,'Russian');
|
||
explain SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's';
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where
|
||
2 DEPENDENT SUBQUERY t2 index_subquery PRIMARY,c c 5 func 1 Using index; Using where
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's';
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where
|
||
2 DEPENDENT SUBQUERY t2 index_subquery PRIMARY,c c 5 func 1 Using index; Using where
|
||
Warnings:
|
||
Note 1003 SELECT SUM(a + SLEEP(0.1)) FROM t1 WHERE a IN ( SELECT c FROM t2 WHERE d < b ) OR b < 's'
|
||
SUM(a + SLEEP(0.1))
|
||
7862
|
||
set debug_dbug=@old_debug;
|
||
drop table t1, t2;
|
||
#
|
||
# MDEV-412: SHOW EXPLAIN: Server crashes in JOIN::print_explain on a query with inner join and ORDER BY the same column twice
|
||
#
|
||
CREATE TABLE t1 (a INT PRIMARY KEY, b VARCHAR(3), KEY(b)) ENGINE=MyISAM;
|
||
INSERT INTO t1 VALUES
|
||
(3795,'USA'),(3913,'USA'),(3846,'ITA'),(4021,'USA'),(4005,'RUS'),(4038,'USA'),
|
||
(3825,'USA'),(3840,'USA'),(3987,'USA'),(3807,'USA'),(3896,'USA'),(4052,'USA'),
|
||
(3973,'USA'),(3982,'ITA'),(3965,'USA'),(3852,'RUS'),(4006,'USA'),(3800,'USA'),
|
||
(4020,'USA'),(4040,'USA'),(3916,'USA'),(3817,'USA'),(3885,'USA'),(3802,'USA'),
|
||
(4009,'ITA'),(3895,'USA'),(3963,'RUS'),(4045,'USA'),(3988,'USA'),(3815,'USA'),
|
||
(4063,'USA'),(3978,'USA'),(4019,'USA'),(3954,'USA'),(3950,'USA'),(3974,'ITA'),
|
||
(4054,'USA'),(4061,'RUS'),(3976,'USA'),(3966,'USA'),(3957,'USA'),(3981,'USA'),
|
||
(3923,'USA'),(3876,'USA'),(3819,'USA'),(3877,'USA'),(3829,'ITA'),(3964,'USA'),
|
||
(4053,'RUS'),(3917,'USA'),(3874,'USA'),(4023,'USA'),(4001,'USA'),(3872,'USA'),
|
||
(3890,'USA'),(3962,'USA'),(3886,'USA'),(4026,'ITA'),(3869,'USA'),(3937,'RUS'),
|
||
(3975,'USA'),(3944,'USA'),(3908,'USA'),(3867,'USA'),(3947,'USA'),(3838,'USA'),
|
||
(3796,'USA'),(3893,'USA'),(3920,'ITA'),(3994,'USA'),(3875,'RUS'),(4011,'USA'),
|
||
(4013,'USA'),(3810,'USA'),(3834,'USA'),(3968,'USA'),(3931,'USA'),(3839,'USA'),
|
||
(4042,'USA'),(4039,'ITA'),(3811,'USA'),(3837,'RUS'),(4041,'USA'),(3884,'USA'),
|
||
(3894,'USA'),(3879,'USA'),(3942,'USA'),(3959,'USA'),(3814,'USA'),(4044,'USA'),
|
||
(3971,'ITA'),(3823,'USA'),(3793,'RUS'),(3855,'USA'),(3905,'USA'),(3865,'USA'),
|
||
(4046,'USA'),(3990,'USA'),(4022,'USA'),(3833,'USA'),(3918,'USA'),(4064,'ITA'),
|
||
(3821,'USA'),(3836,'RUS'),(3921,'USA'),(3914,'USA'),(3888,'USA');
|
||
CREATE TABLE t2 (c VARCHAR(3) PRIMARY KEY) ENGINE=MyISAM;
|
||
INSERT INTO t2 VALUES ('USA');
|
||
CREATE TABLE t3 (d VARCHAR(3), e VARCHAR(52), PRIMARY KEY (d,e)) ENGINE=MyISAM;
|
||
INSERT INTO t3 VALUES
|
||
('JPN','Japanese'),('KOR','Korean'),('POL','Polish'),('PRT','Portuguese'),
|
||
('ESP','Spanish'),('FRA','French'),('VNM','Vietnamese');
|
||
explain
|
||
SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t2 system NULL NULL NULL NULL 1
|
||
1 SIMPLE t1 range b b 6 NULL 107 Using where; Using index
|
||
1 SIMPLE t3 ref PRIMARY PRIMARY 5 test.t1.b 1 Using index
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_do_select';
|
||
SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t2 system NULL NULL NULL NULL 1
|
||
1 SIMPLE t1 range b b 6 NULL 107 Using where; Using index
|
||
1 SIMPLE t3 ref PRIMARY PRIMARY 5 test.t1.b 1 Using index
|
||
Warnings:
|
||
Note 1003 SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2
|
||
field1 field2
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t1,t2,t3;
|
||
#
|
||
# MDEV-423: SHOW EXPLAIN: 'Using where' for a subquery is shown in EXPLAIN, but not in SHOW EXPLAIN output
|
||
#
|
||
CREATE TABLE t1 (a INT) ENGINE=MyISAM;
|
||
INSERT INTO t1 VALUES (7),(0),(9),(3),(4),(2),(5),(7),(0),(9),(3),(4),(2),(5);
|
||
CREATE TABLE t2 (b INT, c INT) ENGINE=MyISAM;
|
||
INSERT INTO t2 VALUES
|
||
(0,4),(8,6),(1,3),(8,5),(9,3),(24,246),(6,2),(1,9),(6,3),(2,8),
|
||
(4,1),(8,8),(4,8),(4,5),(7,7),(4,5),(1,1),(9,6),(4,2),(8,9);
|
||
create table t3 like t2;
|
||
insert into t3 select * from t2;
|
||
explain
|
||
SELECT max(a+b+c) FROM t1 AS alias1, ( SELECT * FROM t2 ) AS alias
|
||
WHERE EXISTS ( SELECT * FROM t3 WHERE b = c ) OR a <= 10;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY alias1 ALL NULL NULL NULL NULL 14
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 20
|
||
3 SUBQUERY t3 ALL NULL NULL NULL NULL 20 Using where
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
SELECT max(a+b+c) FROM t1 AS alias1, ( SELECT * FROM t2 ) AS alias
|
||
WHERE EXISTS ( SELECT * FROM t3 WHERE b = c ) OR a <= 10;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY alias1 ALL NULL NULL NULL NULL 14
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 20
|
||
3 SUBQUERY t3 ALL NULL NULL NULL NULL 20 Using where
|
||
Warnings:
|
||
Note 1003 SELECT max(a+b+c) FROM t1 AS alias1, ( SELECT * FROM t2 ) AS alias
|
||
WHERE EXISTS ( SELECT * FROM t3 WHERE b = c ) OR a <= 10
|
||
max(a+b+c)
|
||
279
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t1,t2,t3;
|
||
#
|
||
# MDEV-416: Server crashes in SQL_SELECT::cleanup on EXPLAIN with SUM ( DISTINCT ) in a non-correlated subquery (5.5-show-explain tree)
|
||
#
|
||
CREATE TABLE t1 (a INT);
|
||
INSERT INTO t1 VALUES (1),(2);
|
||
CREATE TABLE t2 (b INT);
|
||
INSERT INTO t2 VALUES (8),(9);
|
||
EXPLAIN SELECT * FROM t1
|
||
WHERE ( 8, 89 ) IN ( SELECT b, SUM( DISTINCT b ) FROM t2 GROUP BY b );
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
|
||
2 SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using filesort
|
||
DROP TABLE t1,t2;
|
||
#
|
||
# Check if queries in non-default charsets work.
|
||
#
|
||
set names cp1251;
|
||
select charset('<27><>');
|
||
charset('<27><>')
|
||
cp1251
|
||
select hex('<27><>');
|
||
hex('<27><>')
|
||
E3FB
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
select * from t0 where length('<27><>') = a;
|
||
set names utf8;
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 SIMPLE t0 ALL NULL NULL NULL NULL 10 Using where
|
||
Warnings:
|
||
Note 1003 select * from t0 where length('гы') = a
|
||
set names default;
|
||
a
|
||
2
|
||
set debug_dbug=@old_debug;
|
||
set names default;
|
||
#
|
||
# MDEV-462: SHOW EXPLAIN: Assertion `table_list->table' fails in find_field_in_table_ref if FOR contains a non-numeric value
|
||
#
|
||
show explain for foo;
|
||
ERROR HY000: You may only use constant expressions in this statement
|
||
#
|
||
# MDEV-411: SHOW EXPLAIN: For dependent subquery EXPLAIN produces type=index, key, 'Using where; Using index',
|
||
# while SHOW EXPLAIN says type=ALL, no key, 'Range checked for each record'
|
||
#
|
||
CREATE TABLE t1 (a INT NOT NULL, KEY(a)) ENGINE=MyISAM;
|
||
INSERT INTO t1 VALUES (7),(0);
|
||
CREATE TABLE t2 (b INT NOT NULL) ENGINE=MyISAM;
|
||
INSERT INTO t2 VALUES (0),(8);
|
||
explain
|
||
SELECT SUM(b) FROM ( SELECT * FROM t1 ) AS alias1, t2
|
||
WHERE b <= ANY (
|
||
SELECT a FROM t1
|
||
WHERE a = b + SLEEP(0.2) OR a >= ( SELECT SUM(b) FROM t2 ));
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 index NULL a 4 NULL 2 Using index
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where
|
||
3 DEPENDENT SUBQUERY t1 ALL a NULL NULL NULL 2 Range checked for each record (index map: 0x1)
|
||
4 SUBQUERY t2 ALL NULL NULL NULL NULL 2
|
||
set @show_explain_probe_select_id=1;
|
||
set debug_dbug='+d,show_explain_probe_join_exec_start';
|
||
SELECT SUM(b) FROM ( SELECT * FROM t1 ) AS alias1, t2
|
||
WHERE b <= ANY (
|
||
SELECT a FROM t1
|
||
WHERE a = b + SLEEP(0.2) OR a >= ( SELECT SUM(b) FROM t2 ));
|
||
show explain for $thr2;
|
||
id select_type table type possible_keys key key_len ref rows Extra
|
||
1 PRIMARY t1 index NULL a 4 NULL 2 Using index
|
||
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where
|
||
3 DEPENDENT SUBQUERY t1 ALL a NULL NULL NULL 2 Range checked for each record (index map: 0x1)
|
||
4 SUBQUERY t2 ALL NULL NULL NULL NULL 2
|
||
Warnings:
|
||
Note 1003 SELECT SUM(b) FROM ( SELECT * FROM t1 ) AS alias1, t2
|
||
WHERE b <= ANY (
|
||
SELECT a FROM t1
|
||
WHERE a = b + SLEEP(0.2) OR a >= ( SELECT SUM(b) FROM t2 ))
|
||
SUM(b)
|
||
0
|
||
set debug_dbug=@old_debug;
|
||
DROP TABLE t1,t2;
|
||
drop table t0;
|
||
#
|
||
# MDEV-5148: Server crashes in print_explain on killing EXPLAIN EXTENDED
|
||
#
|
||
create table t0 (a int not null);
|
||
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
|
||
create table t1 (a int, b int);
|
||
insert into t1 select a,a from t0;
|
||
create table t2 as select * from t1;
|
||
set @show_explain_probe_select_id=2;
|
||
set debug_dbug='+d,show_explain_probe_best_ext_lim_search';
|
||
explain
|
||
select * from t0
|
||
where not exists ( select 1 from t1, t2 where t1.b=t2.b and t2.a=t0.a) and a is null;
|
||
kill query $thr2;
|
||
ERROR 70100: Query execution was interrupted
|
||
drop table t0,t1,t2;
|
||
# End
|
||
set debug_sync='RESET';
|