1berry/MariaDB-server
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Fixed LP bug #823826.

Browse Source 
The method Item_func_isnull::update_used_tables() erroneously did not
update cached values stored in the fields used_tables_cache and
const_item_cache of the Item_func_isnull objects. As a result the
Item_func_isnull::used_tables() returned wrong bitmaps and, as a
consequence, push-down predicates could be attached to wrong tables.
This commit is contained in:
Igor Babaev 2011-08-11 12:11:04 -07:00
parent 209682577f
commit 4ddea0cb93
3 changed files with 57 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
mysql-test/r/derived_view.result
View File

@ -1214,5 +1214,33 @@ id select_type table type possible_keys key key_len ref rows Extra
SELECT * FROM (SELECT * FROM (SELECT @b) AS t) AS s;
@b
NULL
set optimizer_switch=@exit_optimizer_switch;
set optimizer_switch='derived_merge=on';
#
# LP bug #823826: view over join + IS NULL in WHERE
#
CREATE TABLE t1 (a int) ;
INSERT INTO t1 VALUES (1), (1);
CREATE TABLE t2 (b int) ;
INSERT INTO t2 VALUES (9), (NULL), (7);
CREATE VIEW v1 AS SELECT * FROM t1,t2;
EXPLAIN
SELECT * FROM (SELECT * FROM t1,t2) t WHERE b IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 2
1 SIMPLE t2 ALL NULL NULL NULL NULL 3 Using where; Using join buffer (flat, BNL join)
SELECT * FROM (SELECT * FROM t1,t2) t WHERE b IS NULL;
a b
1 NULL
1 NULL
EXPLAIN
SELECT * FROM v1 WHERE b IS NULL;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 2
1 SIMPLE t2 ALL NULL NULL NULL NULL 3 Using where; Using join buffer (flat, BNL join)
SELECT * FROM v1 WHERE b IS NULL;
a b
1 NULL
1 NULL
DROP VIEW v1;
DROP TABLE t1,t2;
set optimizer_switch=@exit_optimizer_switch;

25
mysql-test/t/derived_view.test
View File

@ -735,7 +735,30 @@ set optimizer_switch='derived_merge=off';
EXPLAIN
SELECT * FROM (SELECT * FROM (SELECT @b) AS t) AS s;
SELECT * FROM (SELECT * FROM (SELECT @b) AS t) AS s;
set optimizer_switch=@exit_optimizer_switch;
set optimizer_switch='derived_merge=on';
--echo #
--echo # LP bug #823826: view over join + IS NULL in WHERE
--echo #
CREATE TABLE t1 (a int) ;
INSERT INTO t1 VALUES (1), (1);
CREATE TABLE t2 (b int) ;
INSERT INTO t2 VALUES (9), (NULL), (7);
CREATE VIEW v1 AS SELECT * FROM t1,t2;
EXPLAIN
SELECT * FROM (SELECT * FROM t1,t2) t WHERE b IS NULL;
SELECT * FROM (SELECT * FROM t1,t2) t WHERE b IS NULL;
EXPLAIN
SELECT * FROM v1 WHERE b IS NULL;
SELECT * FROM v1 WHERE b IS NULL;
DROP VIEW v1;
DROP TABLE t1,t2;
# The following command must be the last one the file
set optimizer_switch=@exit_optimizer_switch;

4
sql/item_cmpfunc.h
View File

@ -1365,7 +1365,11 @@ public:
const_item_cache= 1;
}
else
{
args[0]->update_used_tables();
used_tables_cache= args[0]->used_tables();
const_item_cache= args[0]->const_item();
}
}
table_map not_null_tables() const { return 0; }
optimize_type select_optimize() const { return OPTIMIZE_NULL; }