Even if you are using a GUI tool to connect to your MySQL servers, one day or another, you will have to deal with the command line. So it is nice to know a few tips that can really make your work easier. Note: The commands below are only available for Unix/Linux. Using pager Most [...]
Percona Toolkit Webinar followup Q&A
December 19, 2012 By 1 Comment
First, a thank you to everyone who attended the webinar Today, I appreciate your time and nice comments. As promised, here are answers to questions that couldn’t be answered during the talk: Q: How do you install the tools? The manual has full details, but it’s important to know that the latest release for [...]
Get Me Some Query Logs!
November 22, 2012 By 14 Comments
One of my favorite tools in the Percona Toolkit is pt-query-digest. This tool is indispensable for identifying your top SQL queries, and analyzing which queries are accounting for your database load. But the report you get from pt-query-digest is only as good as the log of queries you give it as input. You need a large [...]
Concatenating MyISAM files
November 19, 2012 By 5 Comments
Recently, I found myself involved in the migration of a large read-only InnoDB database to MyISAM (eventually packed). The only issue was that for one of the table, we were talking of 5 TB of data, 23B rows. Not small… I calculated that with something like insert into MyISAM_table… select * from Innodb_table… would take [...]
Percona Toolkit version 2.1.6 released
November 15, 2012 By 3 Comments
The Percona Toolkit team is happy to announce the release of Percona Toolkit version 2.1.6. This is the sixth stable release in the 2.1 series, and primarily a bug-fix release; We suggest that users upgrade to the latest version of the tools. The complete list of changes is on the Launchpad milestone for 2.1.6, but [...]
Knowing what pt-online-schema-change will do
November 1, 2012 By 1 Comment
pt-online-schema-change is simple to use, but internally it is complex. Baron’s webinar about pt-online-schema-change hinted at several of the tool’s complexities. Consequently, users often want to know before making changes what pt-online-schema-change will do when it runs. The tool has two options to help answer this question: –dry-run and –print. When ran with –dry-run and –print, pt-online-schema-change changes nothing [...]
MySQL and predictive option handling – beware
October 29, 2012 By 2 Comments
MySQL command line utilities have an interesting property – if you only use the prefix of the option or command it will go over the list of available command and if there is only one command with matching prefix it will execute it with no warnings or any kind, otherwise it will report the error. [...]
L2 cache for MySQL
October 25, 2012 By 13 Comments
The idea to use SSD/Flash as a cache is not new, and there are different solutions for this, both OpenSource like L2ARC for ZFS and Flashcache from Facebook, and proprietary, like directCache from Fusion-io. They all however have some limitations, that’s why I am considering to have L2 cache on a database level, as an [...]
Replaying database load with Percona Playback
October 25, 2012 By 9 Comments
If you are planning to upgrade or make any configuration change on your MySQL database the first advice usually is: – Benchmark! How should we do that benchmark? People usually run generic benchmark tools like sysbench, tpcc or mysqlslap that are good to know the number of transactions per seconds that a database can do [...]
Tools and Techniques for Index Design Webinar Questions Followup
October 4, 2012 By 5 Comments
I presented a webinar this week to give an overview of Tools and Techniques for Index Design. Even if you missed the webinar, you can register for it, and you’ll be emailed a link to the recording. I’d like to invite folks who are interested in tools for query optimization to attend the new Percona [...]
