Category Archives: tip

Performance_schema success stories : host summary tables

Posted on March 19, 2014 by aadant

This question was asked at support by a customer to solve a difficult issue. How to identify a sporadic burst of queries coming from one of the hosts accessing the database ? If there are hundreds of hosts, it can … Continue reading →

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50 tips to boost MySQL Performance Webinar follow up

Posted on March 7, 2014 by aadant

Thank you for attending the webinar !  Here are the ppt slides. If you missed it, you can still join the archived event by clicking the URL below. http://w.on24.com/r.htm?e=748845&s=1&k=171F8C0CECD105B0F4ED721CA6F2C704 There were a lot of attendees and a lot of questions. … Continue reading →

Posted in conference, tip, Uncategorized | 2 Comments

How to calculate a specific InnoDB index size ?

Posted on February 4, 2014 by aadant

MySQL provides commands to see the overall index size versus the data size. One of them is “show table status” :

So here, we have these “estimations”, run ANALYZE TABLE before to get more accurate estimates : Data_length: 143310848, … Continue reading →

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A small optimizer change worth noticing

Posted on December 20, 2013 by aadant

MySQL uses internal temporary tables to execute some queries. Usually the tables are stored in memory and on disk if some conditions are met : Some conditions prevent the use of an in-memory temporary table, in which case the server … Continue reading →

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Poor man’s Online Optimize in 5.6

Posted on September 30, 2013 by aadant

Table space fragmentation has generally 2 origins : File System fragmentation : the data file is spread physically on many non contiguous locations on the disk. Internal Fragmentation : the data and index pages have “holes” : this happens when  … Continue reading →

Posted in online DDL, tip | 2 Comments