One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though… to use. Do push concurrency too high Many developers will test script with multiple level of concurrency and find out doing…
Post: Zero-Downtime Schema Changes In MySQL
May 3, 2012 By 2 Comments
…_x table why ? The first question sounds like a potential MySQL bug. Are you sure this is really happening? I would… new version, does it mean the tool has been well tested in replication environment? Yes.
Post: Testing Intel SSD 520
May 1, 2012 By 7 Comments
…. First case is random write asynchronous 8 threads IO, the test is done just after a secure erase operation on the… good question how does it affect MySQL performance, and I am going to run some MySQL workloads on these cards to understand… you are interested more in SSD and MySQL questions – I will be giving a webinary “MySQL and SSD” on May-9. It…
Post: Testing Fusion-io ioDrive
May 3, 2012 By 1 Comment
Following my series of posts on testing different SSD, in my last post I mentioned that SATA … closer to PCIe cards. It really makes sense to test it under MySQL workload, but before getting to that, let me review…
Post: Announcement of Percona XtraDB Cluster 5.5.23
May 14, 2012 By 11 Comments
… and improvements. List of changes: Fixes merged from upstream (Codership-mysql) Support for MyISAM, now changes to MyISAM tables are replicated… best to eliminate bugs and problems during alpha and beta testing release, but this is a software, so bugs are expected…
Post: Percona Server 5.5.22-25.2 released!
April 26, 2012 By Leave a Comment
… available here and from the Percona Software Repositories). Based on MySQL 5.5.22, including all the bug fixes in it…-25.2 milestone at Launchpad. Bugs Fixed: While running the test case found that MEMORY engine may return rows in non…
Comment: InnoDB's gap locks
May 7, 2012 By 15 Comments
… in set (0.00 sec) root@localhost:test 14:51:40> Transaction2: root@localhost:test 14:35:50>start transaction; Query OK… 1207 sec, process no 2909, OS thread id 1100101952 inserting mysql tables in use 1, locked 1 LOCK WAIT 2 lock struct(s), heap size 1216, 1 row lock(s) MySQL thread id 31929, query id 484616 localhost root update insert…
Comment: Percona Replication Manager, a solution for MySQL high availability with replication using Pacemaker
May 16, 2012 By 94 Comments
… Server 12.04 LTS) the pacemaker mysql plugin (ocf:heartbeat:mysql) doesn’t work, because since mysql 5.5 the statement “CHANGE MASTER… in his the last version on gitub. But in my MySQL – installation a “SHOW SLAVE STATUS” will ALWAYS produce a completely… say that this server is a slave, but later the test of “Slave_SQL_Running: Yes” fails, because the server is…
Post: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
…’s come to the MySQL configuration. MySQL Configuration I used Percona Server 5.5.22-55 for the tests. Following is the configuration… was all about the configuration of the EC2 instance and MySQL. Now as far as the benchmark itself is concerned, I…, for a total of 1 billion rows. I ran the test both with the table purchases_noindex which has no secondary…
Comment: GROUP_CONCAT useful GROUP BY extension
May 2, 2012 By 43 Comments
You can chanage separator as follows: mysql> SELECT *, -> GROUP_CONCAT(DISTINCT test_score -> ORDER BY test_score DESC SEPARATOR ‘ |’) -> FROM table_name
