Dear Community, Percona Server version 5.1.47-rel11.0 is available for download now. The changes in this release include: New features Percona Server is now based on MySQL 5.1.47, and XtraDB is now based on InnoDB plugin 1.0.8. XtraDB now uses the fast recovery code released in InnoDB Plugin version 1.0.8, instead of Percona’s earlier fast-recovery code. [...]
How much memory Innodb Dictionary can take ?
May 6, 2010 By 3 Comments
The amount of memory Innodb will require for its data dictionary depends on amount of tables you have as well as number of fields and indexes. Innodb allocates this memory once table is accessed and keeps until server is shut down. In XtraDB we have an option to restrict that limit. So how much memory [...]
Percona-XtraDB-9.1: released and new coming features
March 17, 2010 By 14 Comments
Recently Alexandr announced new Percona-XtraDB-9.1 release, and now it is good time to summarize features we have and what is expected soon. This release contains long waited features from 5.0: extended slow.log USER/TABLE/INDEX/CLIENT_STATISTICS + THREAD_STATISTICS ( coming in release-10) Extended slow.log is now even more extended, there is additional information for each query:
1 | # Bytes_sent: 4973 Tmp_tables: 1 Tmp_disk_tables: 1 Tmp_table_sizes: 7808 |
That [...]
Introducing percona-patches for 5.1
February 9, 2010 By 21 Comments
Our patches for 5.0 have attracted significant interest. You can read about SecondLife’s experience here, as well as what Flickr had to say on their blog. The main improvements come in both performance gains and improvements to diagnostics (such as the improvements to the slow log output, and INDEX_STATISTICS). Despite having many requests to port [...]
How innodb_open_files affects performance
November 18, 2009 By 4 Comments
Recently I looked at table_cache sizing which showed larger table cache does not always provides the best performance. So I decided to look at yet another similar variable – innodb_open_files which defines how many files Innodb will keep open while working in innodb_file_per_table mode. Unlike MyISAM Innodb does not have to keep open file descriptor [...]
How (not) to find unused indexes
October 16, 2009 By 2 Comments
I’ve seen a few people link to an INFORMATION_SCHEMA query to be able to find any indexes that have low cardinality, in an effort to find out what indexes should be removed. This method is flawed – here’s the first reason why:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | CREATE TABLE `sales` ( `id` int(11) NOT NULL AUTO_INCREMENT, `customer_id` int(11) DEFAULT NULL, `status` enum('archived','active') DEFAULT NULL, PRIMARY KEY (`id`), KEY `status` (`status`) ) ENGINE=MyISAM AUTO_INCREMENT=65691 DEFAULT CHARSET=latin1; mysql> SELECT count(*), status FROM sales GROUP by status; +----------+---------+ | count(*) | status | +----------+---------+ |   65536 | archived | |     154 | active | +----------+---------+ 2 rows in set (0.17 sec) mysql> EXPLAIN SELECT * FROM sales WHERE status='active'; # query 1 +----+-------------+-------+------+---------------+--------+---------+-------+------+-------------+ | id | select_type | table | type | possible_keys | key   | key_len | ref  | rows | Extra      | +----+-------------+-------+------+---------------+--------+---------+-------+------+-------------+ | 1 | SIMPLE     | sales | ref | status       | status | 2      | const | 196 | Using where | +----+-------------+-------+------+---------------+--------+---------+-------+------+-------------+ 1 row in set (0.06 sec) mysql> EXPLAIN SELECT * FROM sales WHERE status='archived'; # query 2 +----+-------------+-------+------+---------------+------+---------+------+-------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra      | +----+-------------+-------+------+---------------+------+---------+------+-------+-------------+ | 1 | SIMPLE     | sales | ALL | status       | NULL | NULL   | NULL | 65690 | Using where | +----+-------------+-------+------+---------------+------+---------+------+-------+-------------+ 1 row in set (0.01 sec) |
The cardinality of status index is woeful, but provided that the application [...]
SystemTap – DTrace for Linux ?
September 14, 2009 By 17 Comments
Since DTrace was released for Solaris I am missing it on Linux systems… It can’t be included in Linux by the same reason why ZFS can’t be – it’s licensing issue. Both ZFS and DTrace are under CDDL, which is incompatible with GPL. So you can see DTrace and ZFS on Solaris, FreeBSD, MacOS, but [...]
XtraDB: The Top 10 enhancements
August 13, 2009 By 5 Comments
Note: This post is part 2 of 4 on building our training workshop. Last week I talked about why you don’t want to shard. This week I’m following up with the top 10 enhancements that XtraDB has over the built-in InnoDB included in MySQL 5.0 and 5.1. Building this list was not really a scientific [...]
5.0.83-build17 Percona binaries
July 28, 2009 By 19 Comments
Dear Community, The build 17 of MySQL with Percona patches is available. New features in the release: MySQL-5.0.83 is taken as the basis The new patch innodb_use_sys_malloc.patch is added The new patch innodb_split_buf_pool_mutex.patch is added This patch splits the single global InnoDB buffer pool mutex into several mutexes for different purposes. This reduces mutex contention. [...]
XtraDB storage engine release 1.0.3-6
July 20, 2009 By 6 Comments
Dear community, Today we are pleased to announce release 6 of XtraDB – the result of 2 months hard work. The release includes following new features: MySQL 5.1.36 as a base release New patch
1 | innodb_recovery_patches.patch |
Experimental adaptive checkpoint method estimate innodb_stats – the implementation of the fix forMySQL Bug#30423 expand-import Support of import InnoDB / [...]
