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Fixed LP bug #817360.

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This problem could be observed for queries with nested outer joins
for which the not_exist optimization were applicable. 
The problem was caused by the code of the patch for bug #49322
that erroneously forced the return to the previous nested loop
level when the join algorithm successfully builds a partial record
for an embedded outer to which the not_exist optimization could be
applied.
Actually the immediate return to the previous nested loops level
is correct only if this partial record is rejected by a predicate
pushed down to one of the inner tables of this outer join. Otherwise
attempts to find extensions of this record must be made.
This commit is contained in:
Igor Babaev
2011-07-29 17:09:16 -07:00
parent cfa08e8dad
commit 103c4461ca
4 changed files with 100 additions and 6 deletions
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14
sql/sql_select.cc
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@@ -15114,7 +15114,6 @@ 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)
{
/*
@@ -15130,8 +15129,6 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
first_unmatched->found= 1;
for (JOIN_TAB *tab= first_unmatched; tab <= join_tab; tab++)
{
if (tab->table->reginfo.not_exists_optimize)
use_not_exists_opt= 1;
/* Check all predicates that has just been activated. */
/*
Actually all predicates non-guarded by first_unmatched->found
@@ -15142,7 +15139,11 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
{
/* The condition attached to table tab is false */
if (tab == join_tab)
{
found= 0;
if (tab->table->reginfo.not_exists_optimize)
DBUG_RETURN(NESTED_LOOP_NO_MORE_ROWS);
}
else
{
/*
@@ -15150,7 +15151,10 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
not to the last table of the current nest level.
*/
join->return_tab= tab;
DBUG_RETURN(NESTED_LOOP_OK);
if (tab->table->reginfo.not_exists_optimize)
DBUG_RETURN(NESTED_LOOP_NO_MORE_ROWS);
else
DBUG_RETURN(NESTED_LOOP_OK);
}
}
}
@@ -15164,8 +15168,6 @@ evaluate_join_record(JOIN *join, JOIN_TAB *join_tab,
join_tab->first_unmatched= first_unmatched;
}
if (use_not_exists_opt)
DBUG_RETURN(NESTED_LOOP_NO_MORE_ROWS);
JOIN_TAB *return_tab= join->return_tab;
join_tab->found_match= TRUE;