database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-11-03 14:33:32 +03:00
Code Activity

Bug #37742: HA_EXTRA_KEYREAD flag is set when key contains only prefix of requested

Browse Source 
column
      
When the storage engine uses secondary keys clustered with the primary key MySQL was
adding the primary key parts to each secondary key.
In doing so it was not checking whether the index was on full columns and this
resulted in the secondary keys being added to the list of covering keys even if 
they have partial columns.
Fixed by not adding a primary key part to the list of columns that can be used 
for index read of the secondary keys when the primary key part is a partial key part.
This commit is contained in:
Georgi Kodinov
2008-11-29 15:36:17 +02:00
parent f309f847e4
commit f486bfbbdb
3 changed files with 123 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

84
mysql-test/r/innodb_mysql.result
View File

@@ -1677,3 +1677,87 @@ select @@session.sql_log_bin, @@session.binlog_format, @@session.tx_isolation;
CREATE TABLE t1 ( a INT ) ENGINE=InnoDB;
INSERT INTO t1 VALUES(1);
DROP TABLE t1;
CREATE TABLE foo (a int, b int, c char(10),
PRIMARY KEY (c(3)),
KEY b (b)
) engine=innodb;
CREATE TABLE foo2 (a int, b int, c char(10),
PRIMARY KEY (c),
KEY b (b)
) engine=innodb;
CREATE TABLE bar (a int, b int, c char(10),
PRIMARY KEY (c(3)),
KEY b (b)
) engine=myisam;
INSERT INTO foo VALUES
(1,2,'abcdefghij'), (2,3,''), (3,4,'klmnopqrst'),
(4,5,'uvwxyz'), (5,6,'meotnsyglt'), (4,5,'asfdewe');
INSERT INTO bar SELECT * FROM foo;
INSERT INTO foo2 SELECT * FROM foo;
EXPLAIN SELECT c FROM bar WHERE b>2;;
id 1
select_type SIMPLE
table bar
type ALL
possible_keys b
key NULL
key_len NULL
ref NULL
rows 6
Extra Using where
EXPLAIN SELECT c FROM foo WHERE b>2;;
id 1
select_type SIMPLE
table foo
type ALL
possible_keys b
key NULL
key_len NULL
ref NULL
rows 6
Extra Using where
EXPLAIN SELECT c FROM foo2 WHERE b>2;;
id 1
select_type SIMPLE
table foo2
type range
possible_keys b
key b
key_len 5
ref NULL
rows 3
Extra Using where; Using index
EXPLAIN SELECT c FROM bar WHERE c>2;;
id 1
select_type SIMPLE
table bar
type ALL
possible_keys PRIMARY
key NULL
key_len NULL
ref NULL
rows 6
Extra Using where
EXPLAIN SELECT c FROM foo WHERE c>2;;
id 1
select_type SIMPLE
table foo
type ALL
possible_keys PRIMARY
key NULL
key_len NULL
ref NULL
rows 6
Extra Using where
EXPLAIN SELECT c FROM foo2 WHERE c>2;;
id 1
select_type SIMPLE
table foo2
type index
possible_keys PRIMARY
key b
key_len 5
ref NULL
rows 6
Extra Using where; Using index
DROP TABLE foo, bar, foo2;