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mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00

Fixed MDEV-5424: SELECT using ORDER BY DESC and LIMIT produces unexpected results (InnoDB/XtraDB)

This only happend when using an ORDER BY on a primary key part, where all other key parts where constant.
Remove of duplicated expressions in ORDER BY (as the old code did this in some strange cases)


mysql-test/r/group_by.result:
  Fixed results to take into account that duplicate order by parts are now deleted
mysql-test/r/group_by_innodb.result:
  Ensure extended keys are on
mysql-test/r/innodb_ext_key.result:
  More tests
mysql-test/r/order_by.result:
  More tests
mysql-test/t/group_by.test:
  Fixed results to take into account that duplicate order by parts are now deleted
mysql-test/t/group_by_innodb.test:
  Ensure extended keys are on
mysql-test/t/innodb_ext_key.test:
  More tests
mysql-test/t/order_by.test:
  More tests
sql/sql_select.cc:
  Fixed bug where we looked at extended key parts when we shouldn't
  Remove of duplicated expressions in ORDER BY
sql/table.cc:
  Indentation fixes
This commit is contained in:
Michael Widenius
2014-01-02 15:51:02 +02:00
parent f8c7e3477f
commit c050b5fdf9
10 changed files with 149 additions and 37 deletions

View File

@ -1957,12 +1957,12 @@ UNIQUE INDEX idx (col1));
INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),
(11),(12),(13),(14),(15),(16),(17),(18),(19),(20);
EXPLAIN SELECT col1 AS field1, col1 AS field2
FROM t1 GROUP BY field1, field2;;
FROM t1 GROUP BY field1, field2+0;;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL idx 5 NULL 20 Using index; Using temporary; Using filesort
FLUSH STATUS;
SELECT col1 AS field1, col1 AS field2
FROM t1 GROUP BY field1, field2;;
FROM t1 GROUP BY field1, field2+0;;
field1 field2
1 1
2 2
@ -2054,8 +2054,12 @@ field1 field2
explain
select col1 f1, col1 f2 from t1 order by f2, f1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL idx 5 NULL 20 Using index
explain
select col1 f1, col1 f2 from t1 order by f2, f1+0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL idx 5 NULL 20 Using index; Using filesort
select col1 f1, col1 f2 from t1 order by f2, f1;
select col1 f1, col1 f2 from t1 order by f2, f1+0;
f1 f2
1 1
2 2
@ -2080,7 +2084,7 @@ f1 f2
explain
select col1 f1, col1 f2 from t1 group by f2 order by f2, f1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL idx 5 NULL 7 Using index for group-by; Using temporary; Using filesort
1 SIMPLE t1 range NULL idx 5 NULL 7 Using index for group-by
select col1 f1, col1 f2 from t1 group by f2 order by f2, f1;
f1 f2
1 1
@ -2106,7 +2110,7 @@ f1 f2
explain
select col1 f1, col1 f2 from t1 group by f1, f2 order by f2, f1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL idx 5 NULL 20 Using index; Using temporary; Using filesort
1 SIMPLE t1 index NULL idx 5 NULL 20 Using index
select col1 f1, col1 f2 from t1 group by f1, f2 order by f2, f1;
f1 f2
1 1
@ -2137,10 +2141,10 @@ INSERT INTO t2(col1, col2) VALUES
(1,20),(2,19),(3,18),(4,17),(5,16),(6,15),(7,14),(8,13),(9,12),(10,11),
(11,10),(12,9),(13,8),(14,7),(15,6),(16,5),(17,4),(18,3),(19,2),(20,1);
explain
select col1 f1, col2 f2, col1 f3 from t2 group by f1, f2, f3;
select col1 f1, col2 f2, col1 f3 from t2 group by f1, f2, f3+0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index NULL idx 10 NULL 20 Using index; Using temporary; Using filesort
select col1 f1, col2 f2, col1 f3 from t2 group by f1, f2, f3;
select col1 f1, col2 f2, col1 f3 from t2 group by f1, f2, f3+0;
f1 f2 f3
1 20 1
2 19 2
@ -2163,10 +2167,10 @@ f1 f2 f3
19 2 19
20 1 20
explain
select col1 f1, col2 f2, col1 f3 from t2 order by f1, f2, f3;
select col1 f1, col2 f2, col1 f3 from t2 order by f1, f2, f3+0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index NULL idx 10 NULL 20 Using index; Using filesort
select col1 f1, col2 f2, col1 f3 from t2 order by f1, f2, f3;
select col1 f1, col2 f2, col1 f3 from t2 order by f1, f2, f3+0;
f1 f2 f3
1 20 1
2 19 2

View File

@ -1,3 +1,4 @@
set @save_ext_key_optimizer_switch=@@optimizer_switch;
#
# MDEV-3992 Server crash or valgrind errors in test_if_skip_sort_order/test_if_cheaper_ordering
# on GROUP BY with indexes on InnoDB table
@ -7,13 +8,14 @@ pk INT PRIMARY KEY,
a VARCHAR(1) NOT NULL,
KEY (pk)
) ENGINE=InnoDB;
set optimizer_switch='extended_keys=on';
INSERT INTO t1 VALUES (1,'a'),(2,'b');
EXPLAIN
SELECT COUNT(*), pk field1, pk AS field2
FROM t1 WHERE a = 'r' OR pk = 183
GROUP BY field1, field2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index PRIMARY,pk pk 4 NULL 2 Using where
1 SIMPLE t1 index PRIMARY,pk PRIMARY 4 NULL 2 Using where
SELECT COUNT(*), pk field1, pk AS field2
FROM t1 WHERE a = 'r' OR pk = 183
GROUP BY field1, field2;
@ -22,9 +24,10 @@ EXPLAIN
SELECT COUNT(*), pk field1 FROM t1
WHERE a = 'r' OR pk = 183 GROUP BY field1, field1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index PRIMARY,pk pk 4 NULL 2 Using where
1 SIMPLE t1 index PRIMARY,pk PRIMARY 4 NULL 2 Using where
SELECT COUNT(*), pk field1 FROM t1
WHERE a = 'r' OR pk = 183 GROUP BY field1, field1;
COUNT(*) field1
drop table t1;
End of 5.5 tests
set optimizer_switch=@save_ext_key_optimizer_switch;

View File

@ -987,6 +987,54 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref page_timestamp page_timestamp 4 const 10 Using where
1 SIMPLE t3 eq_ref PRIMARY PRIMARY 4 test.t2.rev_text_id 1
DROP TABLE t1,t2,t3;
#
# MDEV-5424 SELECT using ORDER BY DESC and LIMIT produces unexpected
# results (InnoDB/XtraDB)
#
create table t1 (a bigint not null unique auto_increment, b varchar(10), primary key (a), key (b(2))) engine = myisam default character set utf8;
create table t2 (a bigint not null unique auto_increment, b varchar(10), primary key (a), key (b(2))) engine = innodb default character set utf8;
insert into t1 (b) values (null), (null), (null);
insert into t2 (b) values (null), (null), (null);
set optimizer_switch='extended_keys=on';
explain select a from t1 where b is null order by a desc limit 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref b b 9 const 2 Using where; Using filesort
select a from t1 where b is null order by a desc limit 2;
a
3
2
explain select a from t2 where b is null order by a desc limit 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range b b 9 NULL 3 Using where; Using filesort
select a from t2 where b is null order by a desc limit 2;
a
3
2
set optimizer_switch='extended_keys=off';
explain select a from t2 where b is null order by a desc limit 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range b b 9 NULL 3 Using where; Using filesort
select a from t2 where b is null order by a desc limit 2;
a
3
2
explain select a from t2 where b is null order by a desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index b PRIMARY 8 NULL 3 Using where
select a from t2 where b is null order by a desc;
a
3
2
1
explain select a from t2 where b is null order by a desc,a,a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index b PRIMARY 8 NULL 3 Using where
select a from t2 where b is null order by a desc,a,a;
a
3
2
1
drop table t1, t2;
set optimizer_switch=@save_optimizer_switch;
set optimizer_switch=@save_ext_key_optimizer_switch;
SET SESSION STORAGE_ENGINE=DEFAULT;

View File

@ -357,6 +357,12 @@ id select_type table type possible_keys key key_len ref rows Extra
explain select * from t1 where a = 1 order by b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a a 4 const 5 Using where; Using index
explain select * from t1 where a = 2 and b > 0 order by a desc,b desc,b,a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 9 NULL 5 Using where; Using index
explain select * from t1 where a = 2 and b < 2 order by a desc,a,b desc,a,b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 9 NULL 2 Using where; Using index
select * from t1 where a = 1 order by b desc;
a b c
1 3 b

View File

@ -1336,7 +1336,7 @@ INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),
(11),(12),(13),(14),(15),(16),(17),(18),(19),(20);
let $query0=SELECT col1 AS field1, col1 AS field2
FROM t1 GROUP BY field1, field2;
FROM t1 GROUP BY field1, field2+0;
# Needs to be range to exercise bug
--eval EXPLAIN $query0;
@ -1366,7 +1366,9 @@ LIMIT 3;
explain
select col1 f1, col1 f2 from t1 order by f2, f1;
select col1 f1, col1 f2 from t1 order by f2, f1;
explain
select col1 f1, col1 f2 from t1 order by f2, f1+0;
select col1 f1, col1 f2 from t1 order by f2, f1+0;
explain
select col1 f1, col1 f2 from t1 group by f2 order by f2, f1;
@ -1386,12 +1388,12 @@ INSERT INTO t2(col1, col2) VALUES
(11,10),(12,9),(13,8),(14,7),(15,6),(16,5),(17,4),(18,3),(19,2),(20,1);
explain
select col1 f1, col2 f2, col1 f3 from t2 group by f1, f2, f3;
select col1 f1, col2 f2, col1 f3 from t2 group by f1, f2, f3;
select col1 f1, col2 f2, col1 f3 from t2 group by f1, f2, f3+0;
select col1 f1, col2 f2, col1 f3 from t2 group by f1, f2, f3+0;
explain
select col1 f1, col2 f2, col1 f3 from t2 order by f1, f2, f3;
select col1 f1, col2 f2, col1 f3 from t2 order by f1, f2, f3;
select col1 f1, col2 f2, col1 f3 from t2 order by f1, f2, f3+0;
select col1 f1, col2 f2, col1 f3 from t2 order by f1, f2, f3+0;
DROP VIEW v1;
DROP TABLE t1, t2;

View File

@ -4,6 +4,8 @@
--source include/have_innodb.inc
set @save_ext_key_optimizer_switch=@@optimizer_switch;
--echo #
--echo # MDEV-3992 Server crash or valgrind errors in test_if_skip_sort_order/test_if_cheaper_ordering
--echo # on GROUP BY with indexes on InnoDB table
@ -15,6 +17,8 @@ CREATE TABLE t1 (
KEY (pk)
) ENGINE=InnoDB;
set optimizer_switch='extended_keys=on';
INSERT INTO t1 VALUES (1,'a'),(2,'b');
EXPLAIN
@ -36,3 +40,5 @@ WHERE a = 'r' OR pk = 183 GROUP BY field1, field1;
drop table t1;
--echo End of 5.5 tests
set optimizer_switch=@save_ext_key_optimizer_switch;

View File

@ -662,6 +662,34 @@ ORDER BY rev_timestamp ASC LIMIT 10;
DROP TABLE t1,t2,t3;
--echo #
--echo # MDEV-5424 SELECT using ORDER BY DESC and LIMIT produces unexpected
--echo # results (InnoDB/XtraDB)
--echo #
create table t1 (a bigint not null unique auto_increment, b varchar(10), primary key (a), key (b(2))) engine = myisam default character set utf8;
create table t2 (a bigint not null unique auto_increment, b varchar(10), primary key (a), key (b(2))) engine = innodb default character set utf8;
insert into t1 (b) values (null), (null), (null);
insert into t2 (b) values (null), (null), (null);
set optimizer_switch='extended_keys=on';
explain select a from t1 where b is null order by a desc limit 2;
select a from t1 where b is null order by a desc limit 2;
explain select a from t2 where b is null order by a desc limit 2;
select a from t2 where b is null order by a desc limit 2;
set optimizer_switch='extended_keys=off';
explain select a from t2 where b is null order by a desc limit 2;
select a from t2 where b is null order by a desc limit 2;
explain select a from t2 where b is null order by a desc;
select a from t2 where b is null order by a desc;
explain select a from t2 where b is null order by a desc,a,a;
select a from t2 where b is null order by a desc,a,a;
drop table t1, t2;
set optimizer_switch=@save_optimizer_switch;
set optimizer_switch=@save_ext_key_optimizer_switch;

View File

@ -261,6 +261,9 @@ desc,b desc;
explain select * from t1 where a = 2 and b > 0 order by a desc,b desc;
explain select * from t1 where a = 2 and b < 2 order by a desc,b desc;
explain select * from t1 where a = 1 order by b desc;
explain select * from t1 where a = 2 and b > 0 order by a desc,b desc,b,a;
explain select * from t1 where a = 2 and b < 2 order by a desc,a,b desc,a,b;
select * from t1 where a = 1 order by b desc;
#
# Test things when we don't have NULL keys