…, FRM files, MySQL MyISAM system tables etc. Starting MySQL 5.5 MySQL uses asynchronous IO which should allow it…requests which when can be merged on OS level or RAID controller so we should expect at…table which was not optimized for prolonged period of time, so it reflect natural state of the table…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
… ANALYZE TABLE on both MySQL Versions to see if you can get statistics to be same or close. I should …binary or differently optimized binaries. When you’re about to file a bug or report the problem through MySQL support … Support Engineer can do it for you provided we have complete test case provided…
Post: MySQL Server Memory Usage
May 17, 2006 By 21 Comments
…MySQL Server code and various small static buffers. This is memory which you can consider used when you just start MySQL…tables. myisam_sort_buffer_size used for ALTER TABLE, OPTIMIZE TABLE, REPAIR TABLE…, Hey we want …tables. It also means user having CREATE TABLE privilege should be able to run MySQL…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
…MySQL Security should be treated the following way – if you do not allow any access to MySQL…MySQL will crash when one of internal memory allocations would unexpectedly fail. To give you couple of hints: Temporary Tables…
Post: MySQL Quality of old and new features
October 4, 2007 By 24 Comments
…severity. ORDER By DESC broken for Innodb tables (bug 31001) This is also very interesting… is broken ? Because minor optimization was implemented in MySQL 5.0. Surely Baron is…when MySQL 5.0 just came out (aka minefield) but still they are not at quality levels of base MySQL features. Plus we should…
Post: Can we get faster expression handling in MySQL
March 30, 2010 By 7 Comments
… to explain results are not 100% comparable (as we can see in the table results are even different) and some performance can… hear about. Many other companies looking to optimize MySQL problem, especially in analytics space when expressions should be computed over hundreds of millions of…
Post: Common MySQL traps webinar questions followup
January 17, 2013 By 1 Comment
…a good candidate for optimization. I have even seen…you have a recommendation on when to use ENUM vs…. the table, which may be difficult if the table is …MySQL? If not which versions? The recommendations I made are valid for all versions up to 5.5, and most should…, on the backup side, we‘re focusing on…
Post: What's required to tune MySQL?
July 27, 2011 By 4 Comments
…you should expect to deliver huge wins. If MySQL is …MySQL installations don’t suffer from the variety and severity of problems we write about here. Examples include what happens when…queries The schema design (table design, data types, indexing,… configuring, or of performance optimization, or …
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… giveth, and the database taketh away. Finally, you should think a lot about how you need to…tables… Optimize For I/O It is pretty much inevitable: if you do this kind of data processing in MySQL… MySQL, although we‘re most famous for our knowledge about it. When another tool is the right one, we…
Post: Full table scan vs full index scan performance
November 23, 2012 By 15 Comments
…we get if we force the optimizer to use the index? mysql…should be chosen. Here if we know that the table will always be in memory, we should add the FORCE INDEX hint to ensure optimal…
