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Fixed bug #49322.

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When not-exists optimization was applied to a table that
happened to be an inner table of two outer joins, one
embedded into another, then setting the match flag for
the embedding outer join on could be skipped. This caused
generation of extra null complemented rows.
Made sure that the match flags are set correctly in all cases
when not-exists optimization is used.
This commit is contained in:
Igor Babaev
2010-09-09 21:16:01 -07:00
parent 6f59c41d2d
commit b3cd40e0d2
3 changed files with 103 additions and 1 deletions
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6
sql/sql_select.cc
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@@ -11738,6 +11738,7 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
condition is true => a match is found.
*/
bool found= 1;
bool use_not_exists_opt= 0;
while (join_tab->first_unmatched && found)
{
/*
@@ -11754,7 +11755,7 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
for (JOIN_TAB *tab= first_unmatched; tab <= join_tab; tab++)
{
if (tab->table->reginfo.not_exists_optimize)
return NESTED_LOOP_NO_MORE_ROWS;
use_not_exists_opt= 1;
/* Check all predicates that has just been activated. */
/*
Actually all predicates non-guarded by first_unmatched->found
@@ -11787,6 +11788,9 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
join_tab->first_unmatched= first_unmatched;
}
if (use_not_exists_opt)
return NESTED_LOOP_NO_MORE_ROWS;
/*
It was not just a return to lower loop level when one
of the newly activated predicates is evaluated as false