Hi!
>>>>> "k" == konstantin <konstantin@stripped> writes:
k> Below is the list of changes that have just been committed into a local
k> 5.0 repository of kostja. When kostja does a push these changes will
k> be propagated to the main repository and, within 24 hours after the
k> push, to the public repository.
k> For information on how to access the public repository
k> see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html
k> ChangeSet
k> 1.2032 05/10/11 20:43:13 konstantin@stripped +8 -0
k> A fix and a test case for Bug#12736 "Server crash during a select".
k> The bug was in JOIN::join_free which was wrongly determining that
k> all joins have been already executed and therefore all used tables
k> can be closed.
<cut>
k> +++ 1.377/sql/sql_select.cc 2005-10-11 20:43:06 +04:00
<cut>
k> +void JOIN::join_free()
k> {
k> SELECT_LEX_UNIT *unit;
k> SELECT_LEX *sl;
k> /*
k> Optimization: if not EXPLAIN and we are done with the JOIN,
k> free all tables.
k> */
k> + bool full= (!select_lex->uncacheable && !thd->lex->describe);
k> + bool can_unlock= full;
k> + DBUG_ENTER("JOIN::join_free");
k> cleanup(full);
k> for (unit= select_lex->first_inner_unit(); unit; unit= unit->next_unit())
k> for (sl= unit->first_select(); sl; sl= sl->next_select())
k> {
k> + Item_subselect *subselect= sl->master_unit()->item;
k> + bool full_local= full && (!subselect ||
> subselect->is_evaluated());
k> + /*
k> + If this join is evaluated, we can fully clean it up and clean up all
k> + its underlying joins even if they are correlated -- they will not be
k> + used any more anyway.
k> + If this join is not yet evaluated, we still must clean it up to
k> + close its table cursors -- it may never get evaluated, as in case of
k> + ... HAVING FALSE OR a IN (SELECT ...))
k> + but all table cursors must be closed before the unlock.
k> + */
k> + sl->cleanup_all_joins(full);
k> + /* Can't unlock if at least one JOIN is still needed */
k> + can_unlock= can_unlock && full_local;
k> }
Why have the varible full_lock?
Instead simple replace setting of it to:
can_unlock= can_unlock && (!subselect || subselect->is_evaluated());
ok to push after the above change.
Regards,
Monty
