Hi!
Just out of curiosity, which SCA?
Cheers,
-Brian
On Oct 19, 2009, at 3:45 PM, sca@stripped wrote:
> Hello,
>
> We're pleased to offer the following contribution under the terms of
> SCA:
>
> At file:///home/psergey/dev/mysql-next-fix-subq/
> ------------------------------------------------------------
> revno: 2817
> revision-id: psergey@stripped
> parent: psergey@stripped
> committer: Sergey Petrunya <psergey@stripped>
> branch nick: mysql-next-fix-subq
> timestamp: Mon 2009-07-06 18:33:29 +0400
> message:
> BUG#42742: crash in setup_sj_materialization, Copy_field::set
> - If a semi-join strategy covers certain [first_table; last_table]
> range in join order, do reset the sj_strategy member for all tables
> within the range, except the first one.
> Failure to do so caused EXPLAIN/execution code to try applying two
> strategies at once which would cause all kinds of undesired
> effects.
> === modified file 'mysql-test/r/subselect_sj2.result'
> --- a/mysql-test/r/subselect_sj2.result 2009-03-21 15:31:38 +0000
> +++ b/mysql-test/r/subselect_sj2.result 2009-07-06 14:33:29 +0000
> @@ -689,3 +689,19 @@
> id select_type table type possible_keys key key_len ref rows Extra
> 1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
> noticed after reading const tables
> drop table t1, t2;
> +#
> +# BUG#42742: crash in setup_sj_materialization, Copy_field::set
> +#
> +create table t3 ( c1 year) engine=innodb;
> +insert into t3 values (2135),(2142);
> +create table t2 (c1 tinytext,c2 text,c6 timestamp) engine=innodb;
> +# The following must not crash, EXPLAIN should show one SJ
> strategy, not a mix:
> +explain select 1 from t2 where
> +c2 in (select 1 from t3, t2) and
> +c1 in (select convert(c6,char(1)) from t2);
> +id select_type table type possible_keys key key_len ref rows Extra
> +1 PRIMARY t2 ALL NULL NULL NULL NULL 1 Using where
> +1 PRIMARY t2 ALL NULL NULL NULL NULL 1
> +1 PRIMARY t2 ALL NULL NULL NULL NULL 1 Using where; Using join buffer
> +1 PRIMARY t3 ALL NULL NULL NULL NULL 2 FirstMatch(t2); Using join
> buffer
> +drop table t2, t3;
>
> === modified file 'mysql-test/r/subselect_sj2_jcl6.result'
> --- a/mysql-test/r/subselect_sj2_jcl6.result 2009-06-19 09:12:06 +0000
> +++ b/mysql-test/r/subselect_sj2_jcl6.result 2009-07-06 14:33:29 +0000
> @@ -693,6 +693,22 @@
> id select_type table type possible_keys key key_len ref rows Extra
> 1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
> noticed after reading const tables
> drop table t1, t2;
> +#
> +# BUG#42742: crash in setup_sj_materialization, Copy_field::set
> +#
> +create table t3 ( c1 year) engine=innodb;
> +insert into t3 values (2135),(2142);
> +create table t2 (c1 tinytext,c2 text,c6 timestamp) engine=innodb;
> +# The following must not crash, EXPLAIN should show one SJ
> strategy, not a mix:
> +explain select 1 from t2 where
> +c2 in (select 1 from t3, t2) and
> +c1 in (select convert(c6,char(1)) from t2);
> +id select_type table type possible_keys key key_len ref rows Extra
> +1 PRIMARY t2 ALL NULL NULL NULL NULL 1 Using where
> +1 PRIMARY t2 ALL NULL NULL NULL NULL 1 Using join buffer
> +1 PRIMARY t2 ALL NULL NULL NULL NULL 1 Using where; Using join buffer
> +1 PRIMARY t3 ALL NULL NULL NULL NULL 2 FirstMatch(t2); Using join
> buffer
> +drop table t2, t3;
> set join_cache_level=default;
> show variables like 'join_cache_level';
> Variable_name Value
>
> === modified file 'mysql-test/t/subselect_sj2.test'
> --- a/mysql-test/t/subselect_sj2.test 2009-03-21 15:31:38 +0000
> +++ b/mysql-test/t/subselect_sj2.test 2009-07-06 14:33:29 +0000
> @@ -872,3 +872,15 @@
> explain select 1 from t2 where c2 = any (select log10(null) from t1
> where c6 <null) ;
> drop table t1, t2;
>
> +--echo #
> +--echo # BUG#42742: crash in setup_sj_materialization,
> Copy_field::set
> +--echo #
> +create table t3 ( c1 year) engine=innodb;
> +insert into t3 values (2135),(2142);
> +create table t2 (c1 tinytext,c2 text,c6 timestamp) engine=innodb;
> +-- echo # The following must not crash, EXPLAIN should show one SJ
> strategy, not a mix:
> +explain select 1 from t2 where
> + c2 in (select 1 from t3, t2) and
> + c1 in (select convert(c6,char(1)) from t2);
> +drop table t2, t3;
> +
>
> === modified file 'sql/sql_select.cc'
> --- a/sql/sql_select.cc 2009-07-06 07:57:39 +0000
> +++ b/sql/sql_select.cc 2009-07-06 14:33:29 +0000
> @@ -7916,7 +7916,11 @@
>
> uint i_end= first + join->best_positions[first].n_sj_tables;
> for (uint i= first; i < i_end; i++)
> + {
> + if (i != first)
> + join->best_positions[i].sj_strategy= SJ_OPT_NONE;
> handled_tabs |= join->best_positions[i].table->table->map;
> + }
>
> if (tablenr != first)
> pos->sj_strategy= SJ_OPT_NONE;
>
>
>
> --
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