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MDEV-5401: Wrong result (missing row) on a 2nd execution of PS with exists_to_in=on, MERGE view or a SELECT SQ

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The problem was that the view substitute its fields (on prepare) with reverting the change after execution. After prepare on optimization exists2in convertion substituted arguments of '=' with constsnt '1', but then one of the arguments of '=' was reverted to the view field reference.This lead to incorrect WHERE condition on the second execution.

To fix the problem we replace whole '=' with '1' permannently.
This commit is contained in:
unknown 2014-04-10 12:14:18 +03:00
parent 584c2d0ae9
commit 39afdcddd1
3 changed files with 53 additions and 9 deletions
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23
mysql-test/r/subselect_exists2in.result
View file

@ -862,4 +862,27 @@ i c1 c2 t1_field t2_field
drop table t1,t2,t3;
set optimizer_switch=default;
set optimizer_switch='exists_to_in=on';
#
#MDEV-5401: Wrong result (missing row) on a 2nd execution of PS with
#exists_to_in=on, MERGE view or a SELECT SQ
#
CREATE TABLE t1 (a INT) ENGINE=MyISAM;
INSERT INTO t1 VALUES (1),(2);
CREATE ALGORITHM=MERGE VIEW v1 AS SELECT * FROM t1;
CREATE TABLE t2 (b INT) ENGINE=MyISAM;
INSERT INTO t2 VALUES (2),(3);
SELECT * FROM v1 WHERE EXISTS ( SELECT * FROM t2 t2x, t2 t2y WHERE t2y.b = a );
a
2
PREPARE stmt FROM "SELECT * FROM v1 WHERE EXISTS ( SELECT * FROM t2 t2x, t2 t2y WHERE t2y.b = a )";
EXECUTE stmt;
a
2
EXECUTE stmt;
a
2
deallocate prepare stmt;
drop view v1;
drop table t1,t2;
# End of 10.0 tests
set optimizer_switch=default;

25
mysql-test/t/subselect_exists2in.test
View file

@ -735,5 +735,30 @@ drop table t1,t2,t3;
set optimizer_switch=default;
set optimizer_switch='exists_to_in=on';
--echo #
--echo #MDEV-5401: Wrong result (missing row) on a 2nd execution of PS with
--echo #exists_to_in=on, MERGE view or a SELECT SQ
--echo #
CREATE TABLE t1 (a INT) ENGINE=MyISAM;
INSERT INTO t1 VALUES (1),(2);
CREATE ALGORITHM=MERGE VIEW v1 AS SELECT * FROM t1;
CREATE TABLE t2 (b INT) ENGINE=MyISAM;
INSERT INTO t2 VALUES (2),(3);
SELECT * FROM v1 WHERE EXISTS ( SELECT * FROM t2 t2x, t2 t2y WHERE t2y.b = a );
PREPARE stmt FROM "SELECT * FROM v1 WHERE EXISTS ( SELECT * FROM t2 t2x, t2 t2y WHERE t2y.b = a )";
EXECUTE stmt;
EXECUTE stmt;
deallocate prepare stmt;
drop view v1;
drop table t1,t2;
--echo # End of 10.0 tests
#restore defaults
set optimizer_switch=default;

14
sql/item_subselect.cc
View file

@ -2626,7 +2626,7 @@ static bool check_equality_for_exist2in(Item_func *func,
typedef struct st_eq_field_outer
{
Item_func **eq_ref;
Item **eq_ref;
Item_ident *local_field;
Item *outer_exp;
} EQ_FIELD_OUTER;
@ -2665,7 +2665,7 @@ static bool find_inner_outer_equalities(Item **conds,
&element.outer_exp))
{
found= TRUE;
element.eq_ref= (Item_func **)li.ref();
element.eq_ref= li.ref();
if (result.append(element))
goto alloc_err;
}
@ -2677,7 +2677,7 @@ static bool find_inner_outer_equalities(Item **conds,
&element.outer_exp))
{
found= TRUE;
element.eq_ref= (Item_func **)conds;
element.eq_ref= conds;
if (result.append(element))
goto alloc_err;
}
@ -2700,7 +2700,7 @@ bool Item_exists_subselect::exists2in_processor(uchar *opt_arg)
THD *thd= (THD *)opt_arg;
SELECT_LEX *first_select=unit->first_select(), *save_select;
JOIN *join= first_select->join;
Item_func *eq= NULL, **eq_ref= NULL;
Item **eq_ref= NULL;
Item_ident *local_field= NULL;
Item *outer_exp= NULL;
Item *left_exp= NULL; Item_in_subselect *in_subs;
@ -2774,7 +2774,6 @@ bool Item_exists_subselect::exists2in_processor(uchar *opt_arg)
{
Item *item= it++;
eq_ref= eqs.at(i).eq_ref;
eq= *eq_ref;
local_field= eqs.at(i).local_field;
outer_exp= eqs.at(i).outer_exp;
/* Add the field to the SELECT_LIST */
@ -2789,10 +2788,7 @@ bool Item_exists_subselect::exists2in_processor(uchar *opt_arg)
/* remove the parts from condition */
if (!upper_not || !local_field->maybe_null)
{
eq->arguments()[0]= new Item_int(1);
eq->arguments()[1]= new Item_int(1);
}
*eq_ref= new Item_int(1);
else
{
*eq_ref= new Item_func_isnotnull(