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Fixed bug mdev-11820.

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The fields st_select_lex::cond_pushed_into_where and
st_select_lex::cond_pushed_into_having should be re-initialized
for the unit specifying a derived table at every re-execution
of the query that uses this derived table, because the result
of condition pushdown may be different for different executions.
This commit is contained in:
Igor Babaev
2017-01-24 13:11:26 -08:00
parent 35760c0000
commit 423b7da36f
3 changed files with 148 additions and 0 deletions
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109
mysql-test/r/derived_cond_pushdown.result
View File

@ -8241,3 +8241,112 @@ SELECT * FROM v1 WHERE v1.d IN ( SELECT MIN(d) FROM t2 WHERE 0 );
d
DROP VIEW v1;
DROP TABLE t1,t2;
#
# MDEV-11820: second execution of PS for query
# with false subquery predicate in WHERE
#
CREATE TABLE t1 (c VARCHAR(3)) ENGINE=MyISAM;
INSERT INTO t1 VALUES ('foo'),('bar');
CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t1;
CREATE TABLE t2 (a INT);
INSERT INTO t2 VALUES (3), (4);
PREPARE stmt1 FROM
" SELECT * FROM v1 WHERE 1 IN (SELECT a FROM t2) OR c = 'foo'";
PREPARE stmt2 FROM
"EXPLAIN FORMAT=JSON
SELECT * FROM v1 WHERE 1 IN (SELECT a FROM t2) OR c = 'foo'";
EXECUTE stmt1;
c
foo
EXECUTE stmt2;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "<derived3>",
"access_type": "ALL",
"rows": 2,
"filtered": 100,
"attached_condition": "v1.c = 'foo'",
"materialized": {
"query_block": {
"select_id": 3,
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 2,
"filtered": 100,
"attached_condition": "t1.c = 'foo'"
}
}
}
},
"subqueries": [
{
"query_block": {
"select_id": 2,
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 2,
"filtered": 100,
"attached_condition": "1 = t2.a"
}
}
}
]
}
}
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
EXECUTE stmt1;
c
foo
EXECUTE stmt2;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "<derived3>",
"access_type": "ALL",
"rows": 2,
"filtered": 100,
"attached_condition": "<in_optimizer>(1,<exists>(subquery#2)) or v1.c = 'foo'",
"materialized": {
"query_block": {
"select_id": 3,
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 2,
"filtered": 100
}
}
}
},
"subqueries": [
{
"query_block": {
"select_id": 2,
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 128,
"filtered": 100,
"attached_condition": "1 = t2.a"
}
}
}
]
}
}
DEALLOCATE PREPARE stmt1;
DEALLOCATE PREPARE stmt2;
DROP VIEW v1;
DROP TABLE t1,t2;

34
mysql-test/t/derived_cond_pushdown.test
View File

@ -1319,3 +1319,37 @@ SELECT * FROM v1 WHERE v1.d IN ( SELECT MIN(d) FROM t2 WHERE 0 );
DROP VIEW v1;
DROP TABLE t1,t2;
--echo #
--echo # MDEV-11820: second execution of PS for query
--echo # with false subquery predicate in WHERE
--echo #
CREATE TABLE t1 (c VARCHAR(3)) ENGINE=MyISAM;
INSERT INTO t1 VALUES ('foo'),('bar');
CREATE ALGORITHM=TEMPTABLE VIEW v1 AS SELECT * FROM t1;
CREATE TABLE t2 (a INT);
INSERT INTO t2 VALUES (3), (4);
PREPARE stmt1 FROM
" SELECT * FROM v1 WHERE 1 IN (SELECT a FROM t2) OR c = 'foo'";
PREPARE stmt2 FROM
"EXPLAIN FORMAT=JSON
SELECT * FROM v1 WHERE 1 IN (SELECT a FROM t2) OR c = 'foo'";
EXECUTE stmt1;
EXECUTE stmt2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
INSERT INTO t2 SELECT a+1 FROM t2;
EXECUTE stmt1;
EXECUTE stmt2;
DEALLOCATE PREPARE stmt1;
# the result here will change after the merge with the fix for mdev-11859
DEALLOCATE PREPARE stmt2;
DROP VIEW v1;
DROP TABLE t1,t2;

5
sql/sql_derived.cc
View File

@ -1099,6 +1099,11 @@ bool mysql_derived_reinit(THD *thd, LEX *lex, TABLE_LIST *derived)
unit->types.empty();
/* for derived tables & PS (which can't be reset by Item_subselect) */
unit->reinit_exec_mechanism();
for (st_select_lex *sl= unit->first_select(); sl; sl= sl->next_select())
{
sl->cond_pushed_into_where= NULL;
sl->cond_pushed_into_having= NULL;
}
unit->set_thd(thd);
DBUG_RETURN(FALSE);
}