MySQL Forums
Forum List  »  Quality Assurance

Partition pruning with composite partitioning keys
Posted by: Roderick Groeneveld
Date: July 30, 2012 08:50AM

MySQL Manual for 5.1 says: "This limitation on pruning with composite partitioning keys is removed in MySQL 5.5."
here: http://dev.mysql.com/doc/refman/5.1/en/partitioning-pruning.html

I disagree with this statement. It's still there in 5.5:

mysql> show variables like 'version';
+---------------+-------------+
| Variable_name | Value |
+---------------+-------------+
| version | 5.5.25a-log |
+---------------+-------------+
1 row in set (0.00 sec)

mysql> show create table node_cksum;
| node_cksum | CREATE TABLE `node_cksum` (
`nodeid` int(11) NOT NULL,
`tablename` varchar(64) NOT NULL DEFAULT '',
`recordid` bigint(20) unsigned NOT NULL,
`cksumtype` int(11) NOT NULL DEFAULT '0',
`cksum` text NOT NULL,
`sync` char(128) NOT NULL DEFAULT '',
PRIMARY KEY (`nodeid`,`cksumtype`,`tablename`,`recordid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
/*!50100 PARTITION BY KEY ()
PARTITIONS 12 */ |
-----------------------------------+
1 row in set (0.01 sec)

mysql> explain partitions select * from node_cksum where nodeid = '4' and cksumtype = '1';
+----+-------------+------------+---------------------------------------+------+---------------+---------+---------+-------------+---------+-------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+------------+---------------------------------------+------+---------------+---------+---------+-------------+---------+-------+
| 1 | SIMPLE | node_cksum | p0,p1,p2,p3,p4,p5,p6,p7,p8,p9,p10,p11 | ref | PRIMARY | PRIMARY | 8 | const,const | 1970579 | |
+----+-------------+------------+---------------------------------------+------+---------------+---------+---------+-------------+---------+-------+
1 row in set (0.00 sec)

mysql> explain partitions select * from node_cksum where nodeid = '4' and cksumtype = '1' and recordid = '400400000278377';
+----+-------------+------------+---------------------------------------+------+---------------+---------+---------+-------------+---------+-------------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+------------+---------------------------------------+------+---------------+---------+---------+-------------+---------+-------------+
| 1 | SIMPLE | node_cksum | p0,p1,p2,p3,p4,p5,p6,p7,p8,p9,p10,p11 | ref | PRIMARY | PRIMARY | 8 | const,const | 1995373 | Using where |
+----+-------------+------------+---------------------------------------+------+---------------+---------+---------+-------------+---------+-------------+
1 row in set (0.00 sec)


mysql> explain partitions select * from node_cksum where nodeid = '4' and cksumtype = '1' and tablename = 'items' and recordid = '400400000278377';
+----+-------------+------------+------------+-------+---------------+---------+---------+-------------------------+------+-------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+------------+------------+-------+---------------+---------+---------+-------------------------+------+-------+
| 1 | SIMPLE | node_cksum | p2 | const | PRIMARY | PRIMARY | 210 | const,const,const,const | 1 | |
+----+-------------+------------+------------+-------+---------------+---------+---------+-------------------------+------+-------+
1 row in set (0.00 sec)

Options: ReplyQuote


Subject
Views
Written By
Posted
Partition pruning with composite partitioning keys
2598
July 30, 2012 08:50AM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.