database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

MDEV-16801 seg_fault on a query

Browse Source 
The bug was in the in the code of JOIN::check_for_splittable_materialized()
where the structures describing the fields of a materialized derived
table that potentially could be used in split optimization were build.
As a result of this bug some fields that were not usable for splitting
were detected as usable. This could trigger crashes further in
st_join_table::choose_best_splitting().
This commit is contained in:
Igor Babaev
2018-08-03 14:54:02 -07:00
parent 7749745b7d
commit d453374fc4
3 changed files with 89 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

54
mysql-test/main/derived_cond_pushdown.result
View File

@ -16026,3 +16026,57 @@ SELECT a FROM (SELECT "aa" a) t WHERE f1(t.a, (SELECT MAX('aa') FROM DUAL LIMIT
a
aa
DROP FUNCTION f1;
#
# MDEV-16801: splittable materialized derived/views with
# one grouping field from table without keys
#
CREATE TABLE t1 (a int, b int, INDEX idx_a(a), INDEX idx_b(b)) ENGINE=MYISAM;
CREATE TABLE t2 (c int) ENGINE=MYISAM;
CREATE TABLE t3 (d int) ENGINE=MYISAM;
INSERT INTO t1 VALUES
(77,7), (11,1), (33,3), (44,4), (8,88),
(78,7), (98,9), (38,3), (28,2), (79,7),
(58,5), (42,4), (71,7), (27,2), (91,9);
INSERT INTO t1 SELECT a+100, b+10 FROM t1;
INSERT INTO t2 VALUES
(100), (700), (200), (100), (200);
INSERT INTO t3 VALUES
(3), (4), (1), (8), (3);
ANALYZE tables t1,t2,t3;
Table Op Msg_type Msg_text
test.t1 analyze status OK
test.t2 analyze status OK
test.t3 analyze status OK
SELECT *
FROM t3,
(SELECT t1.b, t2.c
FROM t1, t2
GROUP BY t1.b,t2.c) dt
WHERE t3.d = dt.b;
d b c
3 3 700
3 3 200
3 3 100
4 4 700
4 4 200
4 4 100
1 1 700
1 1 200
1 1 100
3 3 700
3 3 200
3 3 100
EXPLAIN EXTENDED SELECT *
FROM t3,
(SELECT t1.b, t2.c
FROM t1, t2
GROUP BY t1.b,t2.c) dt
WHERE t3.d = dt.b;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t3 ALL NULL NULL NULL NULL 5 100.00 Using where
1 PRIMARY <derived2> ref key0 key0 5 test.t3.d 2 100.00
2 LATERAL DERIVED t1 ref idx_b idx_b 5 test.t3.d 2 100.00 Using index; Using temporary; Using filesort
2 LATERAL DERIVED t2 ALL NULL NULL NULL NULL 5 100.00 Using join buffer (flat, BNL join)
Warnings:
Note 1003 /* select#1 */ select `test`.`t3`.`d` AS `d`,`dt`.`b` AS `b`,`dt`.`c` AS `c` from `test`.`t3` join (/* select#2 */ select `test`.`t1`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t1` join `test`.`t2` where `test`.`t1`.`b` = `test`.`t3`.`d` group by `test`.`t1`.`b`,`test`.`t2`.`c`) `dt` where `dt`.`b` = `test`.`t3`.`d`
DROP TABLE t1,t2,t3;

33
mysql-test/main/derived_cond_pushdown.test
View File

@ -2986,3 +2986,36 @@ END;$$
DELIMITER ;$$
SELECT a FROM (SELECT "aa" a) t WHERE f1(t.a, (SELECT MAX('aa') FROM DUAL LIMIT 1));
DROP FUNCTION f1;
--echo #
--echo # MDEV-16801: splittable materialized derived/views with
--echo # one grouping field from table without keys
--echo #
CREATE TABLE t1 (a int, b int, INDEX idx_a(a), INDEX idx_b(b)) ENGINE=MYISAM;
CREATE TABLE t2 (c int) ENGINE=MYISAM;
CREATE TABLE t3 (d int) ENGINE=MYISAM;
INSERT INTO t1 VALUES
(77,7), (11,1), (33,3), (44,4), (8,88),
(78,7), (98,9), (38,3), (28,2), (79,7),
(58,5), (42,4), (71,7), (27,2), (91,9);
INSERT INTO t1 SELECT a+100, b+10 FROM t1;
INSERT INTO t2 VALUES
(100), (700), (200), (100), (200);
INSERT INTO t3 VALUES
(3), (4), (1), (8), (3);
ANALYZE tables t1,t2,t3;
let $q=
SELECT *
FROM t3,
(SELECT t1.b, t2.c
FROM t1, t2
GROUP BY t1.b,t2.c) dt
WHERE t3.d = dt.b;
eval $q;
eval EXPLAIN EXTENDED $q;
DROP TABLE t1,t2,t3;

3
sql/opt_split.cc
View File

@ -413,7 +413,8 @@ bool JOIN::check_for_splittable_materialized()
for (cand= cand_start; cand < cand_end; cand++)
{
if (cand->underlying_field->field_index + 1 == fldnr)
if (cand->underlying_field->table == table &&
cand->underlying_field->field_index + 1 == fldnr)
{
cand->is_usable_for_ref_access= true;
break;