mariadb/mysql-test/t/subselect3.test
unknown d886ea8fb6 Fixed bug #28375: a query with an NOT IN subquery predicate may cause
a crash when the left operand of the predicate is evaluated to NULL.
It happens when the rows from the inner tables (tables from the subquery)
are accessed by index methods with key values obtained by evaluation of
the left operand of the subquery predicate. When this predicate is
evaluated to NULL an alternative access with full table scan is used
to check whether the result set returned by the subquery is empty or not.
The crash was due to the fact the info about the access methods used for
regular key values was not properly restored after a switch back from the
full scan access method had occurred.
The patch restores this info properly.
The same problem existed for queries with IN subquery predicates if they
were used not at the top level of the queries.


mysql-test/r/subselect3.result:
  Added a test case for bug #28375.
mysql-test/t/subselect3.test:
  Added a test case for bug #28375.
sql/item_subselect.cc:
  Fixed bug #28375: a query with an NOT IN subquery predicate may cause
  a crash when the left operand of the predicate is evaluated to NULL.
  It happens when the rows from the inner tables (tables from the subquery)
  are accessed by index methods with key values obtained by evaluation of
  the left operand of the subquery predicate. When this predicate is
  evaluated to NULL an alternative access with full table scan is used
  to check whether the result set returned by the subquery is empty or not.
  The crash was due to the fact the info about the access methods used for
  regular key values was not properly restored after a switch back from the
  full scan access method had occurred.
  The patch restores this info properly.
sql/sql_select.h:
  Fixed bug #28375: a query with an NOT IN subquery predicate may cause
  a crash when the left operand of the predicate is evaluated to NULL.
  In the JOIN_TAB structure two fields have been added to save info about
  index methods used to access the subquery rows. The saved info is used
  after a switch back from the alternative full scan access method has 
  occurred. The full scan is used when the left operand of the subquery
  predicate is evaluated to NULL.
2007-05-11 19:37:32 -07:00

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--disable_warnings
drop table if exists t0, t1, t2, t3, t4;
--enable_warnings
#
# 1. Subquery with GROUP/HAVING
#
create table t1 (oref int, grp int, ie int) ;
insert into t1 (oref, grp, ie) values
(1, 1, 1),
(1, 1, 1),
(1, 2, NULL),
(2, 1, 3),
(3, 1, 4),
(3, 2, NULL);
# Ok, for
# select max(ie) from t1 where oref=PARAM group by grp
# we'll have:
# PARAM subquery result
# 1 -> {(1), (NULL)} matching + NULL
# 2 -> {(3)} non-matching
# 3 -> {(3), (NULL)} non-matching + NULL
# 4 -> {} empty set
create table t2 (oref int, a int);
insert into t2 values
(1, 1),
(2, 2),
(3, 3),
(4, NULL),
(2, NULL);
# true, false, null, false, null
select a, oref, a in (select max(ie)
from t1 where oref=t2.oref group by grp) Z from t2;
# This must have a trigcond
explain extended
select a, oref, a in (select max(ie)
from t1 where oref=t2.oref group by grp) Z from t2;
# This must not have a trigcond:
explain extended
select a, oref from t2
where a in (select max(ie) from t1 where oref=t2.oref group by grp);
select a, oref, a in (
select max(ie) from t1 where oref=t2.oref group by grp union
select max(ie) from t1 where oref=t2.oref group by grp
) Z from t2;
# Non-correlated subquery, 2 NULL evaluations
create table t3 (a int);
insert into t3 values (NULL), (NULL);
flush status;
select a in (select max(ie) from t1 where oref=4 group by grp) from t3;
show status like 'Handler_read_rnd_next';
select ' ^ This must show 11' Z;
# This must show trigcond:
explain extended select a in (select max(ie) from t1 where oref=4 group by grp) from t3;
drop table t1, t2, t3;
#
# 2. Subquery handled with 'index_subquery':
#
create table t1 (a int, oref int, key(a));
insert into t1 values
(1, 1),
(1, NULL),
(2, 3),
(2, NULL),
(3, NULL);
create table t2 (a int, oref int);
insert into t2 values (1, 1), (2,2), (NULL, 3), (NULL, 4);
select oref, a, a in (select a from t1 where oref=t2.oref) Z from t2;
# The next explain shows "using index" but that is just incorrect display
# (there is a bug filed about this).
explain extended
select oref, a, a in (select a from t1 where oref=t2.oref) Z from t2;
flush status;
select oref, a from t2 where a in (select a from t1 where oref=t2.oref);
# This will only show access to t2:
show status like '%Handler_read_rnd_next';
# Check that repeated NULL-scans are not cached (subq. is not correlated):
delete from t2;
insert into t2 values (NULL, 0),(NULL, 0), (NULL, 0), (NULL, 0);
flush status;
select oref, a, a in (select a from t1 where oref=t2.oref) Z from t2;
show status like '%Handler_read%';
select 'No key lookups, seq reads: 29= 5 reads from t2 + 4 * 6 reads from t1.' Z;
drop table t1, t2;
#
# 3. Subquery handled with 'unique_index_subquery':
#
create table t1 (a int, b int, primary key (a));
insert into t1 values (1,1), (3,1),(100,1);
create table t2 (a int, b int);
insert into t2 values (1,1),(2,1),(NULL,1),(NULL,0);
select a,b, a in (select a from t1 where t1.b = t2.b) Z from t2 ;
drop table t1, t2;
#
# 4. Subquery that is a join, with ref access
#
create table t1 (a int, b int, key(a));
insert into t1 values
(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
create table t2 like t1;
insert into t2 select * from t1;
update t2 set b=1;
create table t3 (a int, oref int);
insert into t3 values (1, 1), (NULL,1), (NULL,0);
select a, oref,
t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
from t3;
# This must have trigcond in WHERE and HAVING:
explain extended
select a, oref,
t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
from t3;
drop table t1, t2, t3;
#
# BUG#24085: Wrong query result for "NULL IN (SELECT ... UNION SELECT ...)"
#
# case 1: NULL IN (SELECT not_null_val FROM ...) w/o HAVING/GROUP-BY/etc
create table t1 (a int NOT NULL, b int NOT NULL, key(a));
insert into t1 values
(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
create table t2 like t1;
insert into t2 select * from t1;
update t2 set b=1;
create table t3 (a int, oref int);
insert into t3 values (1, 1), (NULL,1), (NULL,0);
select a, oref,
t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
from t3;
--echo This must show a trig_cond:
explain extended
select a, oref,
t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
from t3;
drop table t1,t2,t3;
# case 2: NULL IN (SELECT not_null_val FROM) where SELECT has GROUP BY
create table t1 (oref int, grp int);
insert into t1 (oref, grp) values
(1, 1),
(1, 1);
# Ok, for
# select count(*) from t1 group by grp having grp=PARAM
# we'll have:
# PARAM subuqery result
# 1 -> {(2)}
# 2 -> {} - empty set
create table t2 (oref int, a int);
insert into t2 values
(1, NULL),
(2, NULL);
select a, oref,
a in (select count(*) from t1 group by grp having grp=t2.oref) Z from t2;
--echo This must show a trig_cond:
explain extended
select a, oref,
a in (select count(*) from t1 group by grp having grp=t2.oref) Z from t2;
drop table t1, t2;
create table t1 (a int, b int, primary key (a));
insert into t1 values (1,1), (3,1),(100,1);
create table t2 (a int, b int);
insert into t2 values (1,1),(2,1),(NULL,1),(NULL,0);
select a,b, a in (select a from t1 where t1.b = t2.b union select a from
t1 where t1.b = t2.b) Z from t2 ;
select a,b, a in (select a from t1 where t1.b = t2.b) Z from t2 ;
drop table t1, t2;
#
# BUG#24127: Incorrect results of row-based subqueries with NULLs on the left side.
#
create table t3 (a int);
insert into t3 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t2 (a int, b int, oref int);
insert into t2 values (NULL,1, 100), (NULL,2, 100);
create table t1 (a int, b int, c int, key(a,b));
insert into t1 select 2*A, 2*A, 100 from t3;
# First test index subquery engine
explain extended select a,b, oref, (a,b) in (select a,b from t1 where c=t2.oref) Z from t2;
select a,b, oref, (a,b) in (select a,b from t1 where c=t2.oref) Z from t2;
# Then check that we do turn off 'ref' scans in the subquery
create table t4 (x int);
insert into t4 select A.a + 10*B.a from t1 A, t1 B;
explain extended
select a,b, oref,
(a,b) in (select a,b from t1,t4 where c=t2.oref) Z
from t2;
select a,b, oref,
(a,b) in (select a,b from t1,t4 where c=t2.oref) Z
from t2;
drop table t1,t2,t3,t4;
# More tests for tricky multi-column cases, where some of pushed-down
# equalities are used for index lookups and some arent.
create table t1 (oref char(4), grp int, ie1 int, ie2 int);
insert into t1 (oref, grp, ie1, ie2) values
('aa', 10, 2, 1),
('aa', 10, 1, 1),
('aa', 20, 2, 1),
('bb', 10, 3, 1),
('cc', 10, 4, 2),
('cc', 20, 3, 2),
('ee', 10, 2, 1),
('ee', 10, 1, 2),
('ff', 20, 2, 2),
('ff', 20, 1, 2);
create table t2 (oref char(4), a int, b int);
insert into t2 values
('ee', NULL, 1),
('bb', 2, 1),
('ff', 2, 2),
('cc', 3, NULL),
('bb', NULL, NULL),
('aa', 1, 1),
('dd', 1, NULL);
alter table t1 add index idx(ie1,ie2);
--cc 3 NULL NULL
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2 where a=3 and b is null ;
insert into t2 values ('new1', 10,10);
insert into t1 values ('new1', 1234, 10, NULL);
-- new1, 10, 10, NULL,
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2 where a=10 and b=10;
explain extended
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2 where a=10 and b=10;
drop table t1, t2;
# Now test different column types:
create table t1 (oref char(4), grp int, ie int);
insert into t1 (oref, grp, ie) values
('aa', 10, 2),
('aa', 10, 1),
('aa', 20, NULL),
('bb', 10, 3),
('cc', 10, 4),
('cc', 20, NULL),
('ee', 10, NULL),
('ee', 10, NULL),
('ff', 20, 2),
('ff', 20, 1);
create table t2 (oref char(4), a int);
insert into t2 values
('ee', NULL),
('bb', 2),
('ff', 2),
('cc', 3),
('aa', 1),
('dd', NULL),
('bb', NULL);
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
select oref, a from t2 where a in (select ie from t1 where oref=t2.oref);
select oref, a from t2 where a not in (select ie from t1 where oref=t2.oref);
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by grp) Z from t2;
select oref, a from t2 where
a in (select min(ie) from t1 where oref=t2.oref group by grp);
select oref, a from t2 where
a not in (select min(ie) from t1 where oref=t2.oref group by grp);
#
update t1 set ie=3 where oref='ff' and ie=1;
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by
grp) Z from t2;
select oref, a from t2 where a in (select min(ie) from t1 where
oref=t2.oref group by grp);
select oref, a from t2 where a not in (select min(ie) from t1 where
oref=t2.oref group by grp);
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by
grp having min(ie) > 1) Z from t2;
select oref, a from t2 where a in (select min(ie) from t1 where
oref=t2.oref group by grp having min(ie) > 1);
select oref, a from t2 where a not in (select min(ie) from t1 where
oref=t2.oref group by grp having min(ie) > 1);
#
alter table t1 add index idx(ie);
explain select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
select oref, a from t2 where a in (select ie from t1 where oref=t2.oref);
select oref, a from t2 where a not in (select ie from t1 where oref=t2.oref);
alter table t1 drop index idx;
alter table t1 add index idx(oref,ie);
explain select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
select oref, a from t2 where a in (select ie from t1 where oref=t2.oref);
select oref, a from t2 where a not in (select ie from t1 where oref=t2.oref);
explain
select oref, a,
a in (select min(ie) from t1 where oref=t2.oref
group by grp having min(ie) > 1) Z
from t2;
select oref, a,
a in (select min(ie) from t1 where oref=t2.oref
group by grp having min(ie) > 1) Z
from t2;
select oref, a from t2 where a in (select min(ie) from t1 where oref=t2.oref
group by grp having min(ie) > 1);
select oref, a from t2 where a not in (select min(ie) from t1 where oref=t2.oref
group by grp having min(ie) > 1);
drop table t1,t2;
create table t1 (oref char(4), grp int, ie1 int, ie2 int);
insert into t1 (oref, grp, ie1, ie2) values
('aa', 10, 2, 1),
('aa', 10, 1, 1),
('aa', 20, 2, 1),
('bb', 10, 3, 1),
('cc', 10, 4, 2),
('cc', 20, 3, 2),
('ee', 10, 2, 1),
('ee', 10, 1, 2),
('ff', 20, 2, 2),
('ff', 20, 1, 2);
create table t2 (oref char(4), a int, b int);
insert into t2 values
('ee', NULL, 1),
('bb', 2, 1),
('ff', 2, 2),
('cc', 3, NULL),
('bb', NULL, NULL),
('aa', 1, 1),
('dd', 1, NULL);
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2;
select oref, a, b from t2 where (a,b) in (select ie1,ie2 from t1 where oref=t2.oref);
select oref, a, b from t2 where (a,b) not in (select ie1,ie2 from t1 where oref=t2.oref);
select oref, a, b,
(a,b) in (select min(ie1),max(ie2) from t1
where oref=t2.oref group by grp) Z
from t2;
select oref, a, b from t2 where
(a,b) in (select min(ie1), max(ie2) from t1 where oref=t2.oref group by grp);
select oref, a, b from t2 where
(a,b) not in (select min(ie1), max(ie2) from t1 where oref=t2.oref group by grp);
alter table t1 add index idx(ie1,ie2);
explain select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2;
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2;
select oref, a, b from t2 where (a,b) in (select ie1,ie2 from t1 where oref=t2.oref);
select oref, a, b from t2 where (a,b) not in (select ie1,ie2 from t1 where oref=t2.oref);
explain extended
select oref, a, b, (a,b) in (select ie1,ie2 from t1 where oref=t2.oref) Z from t2;
drop table t1,t2;
create table t1 (oref char(4), grp int, ie int primary key);
insert into t1 (oref, grp, ie) values
('aa', 10, 2),
('aa', 10, 1),
('bb', 10, 3),
('cc', 10, 4),
('cc', 20, 5),
('cc', 10, 6);
create table t2 (oref char(4), a int);
insert into t2 values
('ee', NULL),
('bb', 2),
('cc', 5),
('cc', 2),
('cc', NULL),
('aa', 1),
('bb', NULL);
explain select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
select oref, a from t2 where a in (select ie from t1 where oref=t2.oref);
select oref, a from t2 where a not in (select ie from t1 where oref=t2.oref);
explain
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by grp) Z from t2;
select oref, a, a in (select min(ie) from t1 where oref=t2.oref group by grp) Z from t2;
drop table t1,t2;
#
# BUG#24420: row-based IN suqueries with aggregation when the left operand
# of the subquery predicate may contain NULL values
#
create table t1 (a int, b int);
insert into t1 values (0,0), (2,2), (3,3);
create table t2 (a int, b int);
insert into t2 values (1,1), (3,3);
select a, b, (a,b) in (select a, min(b) from t2 group by a) Z from t1;
insert into t2 values (NULL,4);
select a, b, (a,b) in (select a, min(b) from t2 group by a) Z from t1;
drop table t1,t2;
#
# Bug #24484: Aggregate function used in column list subquery gives erroneous
# error
#
CREATE TABLE t1 (a int, b INT, c CHAR(10) NOT NULL, PRIMARY KEY (a, b));
INSERT INTO t1 VALUES (1,1,'a'), (1,2,'b'), (1,3,'c'), (1,4,'d'), (1,5,'e'),
(2,1,'f'), (2,2,'g'), (2,3,'h'), (3,4,'i'),(3,3,'j'), (3,2,'k'), (3,1,'l'),
(1,9,'m');
CREATE TABLE t2 (a int, b INT, c CHAR(10) NOT NULL, PRIMARY KEY (a, b));
INSERT INTO t2 SELECT * FROM t1;
# Gives error, but should work since it is (a, b) is the PK so only one
# given match possible
SELECT a, MAX(b), (SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b))
as test FROM t1 GROUP BY a;
SELECT * FROM t1 GROUP by t1.a
HAVING (MAX(t1.b) > (SELECT MAX(t2.b) FROM t2 WHERE t2.c < t1.c
HAVING MAX(t2.b+t1.a) < 10));
SELECT a,b,c FROM t1 WHERE b in (9,3,4) ORDER BY b,c;
SELECT a, MAX(b),
(SELECT COUNT(DISTINCT t.c) FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b)
LIMIT 1)
as cnt,
(SELECT t.b FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b) LIMIT 1)
as t_b,
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b) LIMIT 1)
as t_b,
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b) ORDER BY t.c LIMIT 1)
as t_b
FROM t1 GROUP BY a;
SELECT a, MAX(b),
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b) LIMIT 1) as test
FROM t1 GROUP BY a;
DROP TABLE t1, t2;
#
# Bug #27870: crash of an equijoin query with WHERE condition containing
# a subquery predicate of the form <join attr> NOT IN (SELECT ...)
#
CREATE TABLE t1 (a int);
CREATE TABLE t2 (b int, PRIMARY KEY(b));
INSERT INTO t1 VALUES (1), (NULL), (4);
INSERT INTO t2 VALUES (3), (1),(2), (5), (4), (7), (6);
EXPLAIN EXTENDED
SELECT a FROM t1, t2 WHERE a=b AND (b NOT IN (SELECT a FROM t1));
SELECT a FROM t1, t2 WHERE a=b AND (b NOT IN (SELECT a FROM t1));
SELECT a FROM t1, t2 WHERE a=b AND (b NOT IN (SELECT a FROM t1 WHERE a > 4));
DROP TABLE t1,t2;
#
# Bug #28375: crash for NOT IN subquery predicate when left operand becomes NULL
#
CREATE TABLE t1 (id int);
CREATE TABLE t2 (id int PRIMARY KEY);
CREATE TABLE t3 (id int PRIMARY KEY, name varchar(10));
INSERT INTO t1 VALUES (2), (NULL), (3), (1);
INSERT INTO t2 VALUES (234), (345), (457);
INSERT INTO t3 VALUES (222,'bbb'), (333,'ccc'), (111,'aaa');
EXPLAIN
SELECT * FROM t1
WHERE t1.id NOT IN (SELECT t2.id FROM t2,t3
WHERE t3.name='xxx' AND t2.id=t3.id);
SELECT * FROM t1
WHERE t1.id NOT IN (SELECT t2.id FROM t2,t3
WHERE t3.name='xxx' AND t2.id=t3.id);
SELECT (t1.id IN (SELECT t2.id FROM t2,t3
WHERE t3.name='xxx' AND t2.id=t3.id)) AS x
FROM t1;
DROP TABLE t1,t2,t3;