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Commit e670c71e authored by Georgi Kodinov's avatar Georgi Kodinov
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Bug #36259 (Optimizing with ORDER BY) and bug#45828 (Optimizer won't 

use partial primary key if another index can prevent filesort

The fix for bug #28404 causes the covering ordering indexes to be 
preferred unconditionally over non-covering and ref indexes.

Fixed by comparing the cost of using a covering index to the cost of
using a ref index even for covering ordering indexes.
Added an assertion to clarify the condition the local variables should
be in.

mysql-test/include/mix1.inc:
  Bug #36259: fixed a non-stable test case
mysql-test/r/innodb_mysql.result:
  Bug #36259 and #45828 : test case
mysql-test/t/innodb_mysql.test:
  Bug #36259 and #45828 : test case
sql/sql_select.cc:
  Bug #36259 and #45828 : don't consider covering indexes supperior to
  ref keys.
parent afb316db
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Showing with 166 additions and 6 deletions
mysql-test/include/mix1.inc
View file @ e670c71e
......@@ -1498,9 +1498,9 @@ INSERT INTO t1 VALUES
(4,1,3,'pk',NULL),(5,1,3,'c2',NULL),
(2,1,4,'c_extra',NULL),(3,1,4,'c_extra',NULL);
EXPLAIN SELECT * FROM t1 WHERE tid = 1 AND vid = 3 ORDER BY idx DESC;
EXPLAIN SELECT * FROM t1 FORCE INDEX (PRIMARY) WHERE tid = 1 AND vid = 3 ORDER BY idx DESC;
SELECT * FROM t1 WHERE tid = 1 AND vid = 3 ORDER BY idx DESC;
SELECT * FROM t1 FORCE INDEX (PRIMARY) WHERE tid = 1 AND vid = 3 ORDER BY idx DESC;
DROP TABLE t1;
......
mysql-test/r/innodb_mysql.result
View file @ e670c71e
......@@ -1701,10 +1701,10 @@ INSERT INTO t1 VALUES
(4,1,2,'c2',NULL),(5,1,2,'c1',NULL),(2,1,3,'c2',NULL),(3,1,3,'c2',NULL),
(4,1,3,'pk',NULL),(5,1,3,'c2',NULL),
(2,1,4,'c_extra',NULL),(3,1,4,'c_extra',NULL);
EXPLAIN SELECT * FROM t1 WHERE tid = 1 AND vid = 3 ORDER BY idx DESC;
EXPLAIN SELECT * FROM t1 FORCE INDEX (PRIMARY) WHERE tid = 1 AND vid = 3 ORDER BY idx DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index vid PRIMARY 12 NULL 16 Using where
SELECT * FROM t1 WHERE tid = 1 AND vid = 3 ORDER BY idx DESC;
1 SIMPLE t1 index NULL PRIMARY 12 NULL 16 Using where
SELECT * FROM t1 FORCE INDEX (PRIMARY) WHERE tid = 1 AND vid = 3 ORDER BY idx DESC;
vid tid idx name type
3 1 4 c_extra NULL
3 1 3 c2 NULL
......@@ -2137,4 +2137,75 @@ GROUP BY t1.b;
a b c d a b e a b
1 1 1 0 1 1 2 1 1
DROP TABLE t1, t2, t3;
#
# Bug #45828: Optimizer won't use partial primary key if another
# index can prevent filesort
#
CREATE TABLE `t1` (
c1 int NOT NULL,
c2 int NOT NULL,
c3 int NOT NULL,
PRIMARY KEY (c1,c2),
KEY (c3)
) ENGINE=InnoDB;
INSERT INTO t1 VALUES (5,2,1246276747);
INSERT INTO t1 VALUES (2,1,1246281721);
INSERT INTO t1 VALUES (7,3,1246281756);
INSERT INTO t1 VALUES (4,2,1246282139);
INSERT INTO t1 VALUES (3,1,1246282230);
INSERT INTO t1 VALUES (1,0,1246282712);
INSERT INTO t1 VALUES (8,3,1246282765);
INSERT INTO t1 SELECT c1+10,c2+10,c3+10 FROM t1;
INSERT INTO t1 SELECT c1+100,c2+100,c3+100 from t1;
INSERT INTO t1 SELECT c1+1000,c2+1000,c3+1000 from t1;
INSERT INTO t1 SELECT c1+10000,c2+10000,c3+10000 from t1;
INSERT INTO t1 SELECT c1+100000,c2+100000,c3+100000 from t1;
INSERT INTO t1 SELECT c1+1000000,c2+1000000,c3+1000000 from t1;
SELECT * FROM t1 WHERE c1 = 99999999 AND c3 > 1 ORDER BY c3;
c1 c2 c3
EXPLAIN SELECT * FROM t1 WHERE c1 = 99999999 AND c3 > 1 ORDER BY c3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref PRIMARY,c3 PRIMARY 4 const 1 Using where; Using filesort
EXPLAIN SELECT * FROM t1 FORCE INDEX (PRIMARY) WHERE c1 = 99999999 AND c3 > 1 ORDER BY c3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref PRIMARY PRIMARY 4 const 1 Using where; Using filesort
CREATE TABLE t2 (
c1 int NOT NULL,
c2 int NOT NULL,
c3 int NOT NULL,
KEY (c1,c2),
KEY (c3)
) ENGINE=InnoDB;
explain SELECT * FROM t2 WHERE c1 = 99999999 AND c3 > 1 ORDER BY c3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref c1,c3 c1 4 const 1 Using where; Using filesort
DROP TABLE t1,t2;
#
# 36259: Optimizing with ORDER BY
#
CREATE TABLE t1 (
a INT NOT NULL AUTO_INCREMENT,
b INT NOT NULL,
c INT NOT NULL,
d VARCHAR(5),
e INT NOT NULL,
PRIMARY KEY (a), KEY i2 (b,c,d)
) ENGINE=InnoDB;
INSERT INTO t1 (b,c,d,e) VALUES (1,1,'a',1), (2,2,'b',2);
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
EXPLAIN SELECT * FROM t1 WHERE b=1 AND c=1 ORDER BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref i2 i2 8 const,const 1 Using where; Using filesort
EXPLAIN SELECT * FROM t1 FORCE INDEX(i2) WHERE b=1 and c=1 ORDER BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref i2 i2 8 const,const 1 Using where; Using filesort
EXPLAIN SELECT * FROM t1 FORCE INDEX(PRIMARY) WHERE b=1 AND c=1 ORDER BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 4 NULL 128 Using where
DROP TABLE t1;
End of 5.1 tests
mysql-test/t/innodb_mysql.test
View file @ e670c71e
......@@ -380,4 +380,85 @@ SELECT * FROM t1, t2, t3
DROP TABLE t1, t2, t3;
--echo #
--echo # Bug #45828: Optimizer won't use partial primary key if another
--echo # index can prevent filesort
--echo #
# Create the table
CREATE TABLE `t1` (
c1 int NOT NULL,
c2 int NOT NULL,
c3 int NOT NULL,
PRIMARY KEY (c1,c2),
KEY (c3)
) ENGINE=InnoDB;
# populate with data
INSERT INTO t1 VALUES (5,2,1246276747);
INSERT INTO t1 VALUES (2,1,1246281721);
INSERT INTO t1 VALUES (7,3,1246281756);
INSERT INTO t1 VALUES (4,2,1246282139);
INSERT INTO t1 VALUES (3,1,1246282230);
INSERT INTO t1 VALUES (1,0,1246282712);
INSERT INTO t1 VALUES (8,3,1246282765);
INSERT INTO t1 SELECT c1+10,c2+10,c3+10 FROM t1;
INSERT INTO t1 SELECT c1+100,c2+100,c3+100 from t1;
INSERT INTO t1 SELECT c1+1000,c2+1000,c3+1000 from t1;
INSERT INTO t1 SELECT c1+10000,c2+10000,c3+10000 from t1;
INSERT INTO t1 SELECT c1+100000,c2+100000,c3+100000 from t1;
INSERT INTO t1 SELECT c1+1000000,c2+1000000,c3+1000000 from t1;
# query and no rows will match the c1 condition, whereas all will match c3
SELECT * FROM t1 WHERE c1 = 99999999 AND c3 > 1 ORDER BY c3;
# SHOULD use the pk.
# index on c3 will be used instead of primary key
EXPLAIN SELECT * FROM t1 WHERE c1 = 99999999 AND c3 > 1 ORDER BY c3;
# if we force the primary key, we can see the estimate is 1
EXPLAIN SELECT * FROM t1 FORCE INDEX (PRIMARY) WHERE c1 = 99999999 AND c3 > 1 ORDER BY c3;
CREATE TABLE t2 (
c1 int NOT NULL,
c2 int NOT NULL,
c3 int NOT NULL,
KEY (c1,c2),
KEY (c3)
) ENGINE=InnoDB;
# SHOULD use the pk.
# if we switch it from a primary key to a regular index, it works correctly as well
explain SELECT * FROM t2 WHERE c1 = 99999999 AND c3 > 1 ORDER BY c3;
DROP TABLE t1,t2;
--echo #
--echo # 36259: Optimizing with ORDER BY
--echo #
CREATE TABLE t1 (
a INT NOT NULL AUTO_INCREMENT,
b INT NOT NULL,
c INT NOT NULL,
d VARCHAR(5),
e INT NOT NULL,
PRIMARY KEY (a), KEY i2 (b,c,d)
) ENGINE=InnoDB;
INSERT INTO t1 (b,c,d,e) VALUES (1,1,'a',1), (2,2,'b',2);
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
INSERT INTO t1 (b,c,d,e) SELECT RAND()*10000, RAND()*10000, d, e FROM t1;
EXPLAIN SELECT * FROM t1 WHERE b=1 AND c=1 ORDER BY a;
EXPLAIN SELECT * FROM t1 FORCE INDEX(i2) WHERE b=1 and c=1 ORDER BY a;
EXPLAIN SELECT * FROM t1 FORCE INDEX(PRIMARY) WHERE b=1 AND c=1 ORDER BY a;
DROP TABLE t1;
--echo End of 5.1 tests
sql/sql_select.cc
View file @ e670c71e
......@@ -13132,9 +13132,17 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
for (nr=0; nr < table->s->keys ; nr++)
{
int direction;
if (keys.is_set(nr) &&
(direction= test_if_order_by_key(order, table, nr, &used_key_parts)))
{
/*
At this point we are sure that ref_key is a non-ordering
key (where "ordering key" is a key that will return rows
in the order required by ORDER BY).
*/
DBUG_ASSERT (ref_key != (int) nr);
bool is_covering= table->covering_keys.is_set(nr) ||
(nr == table->s->primary_key &&
table->file->primary_key_is_clustered());
......@@ -13215,7 +13223,7 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
*/
index_scan_time= select_limit/rec_per_key *
min(rec_per_key, table->file->scan_time());
if (is_covering ||
if ((ref_key < 0 && is_covering) ||
(ref_key < 0 && (group || table->force_index)) ||
index_scan_time < read_time)
{
......
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