… performance problems with MySQL is what they happen every so often or certain times. Investigating them we find out what the cause is… is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing these does help in…. So what you can do to prevent this problem from happening ? The answer is easy. Throttle the side load so it does not…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…both MySQL 5.6 and MariaDB 5.5 Now let’s take a look at what this optimization actually is and what… means that secondary key lookups for column values that do not belong to the secondary index definition can …for MariaDB 5.5 when compared to MySQL 5.5, and this does not make sense to me. Probably its…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… these optimizations. Batched Key Access Traditionally, MySQL always uses Nested Loop Join to join two or more tables. What… if the caches are not warm, this also does not take into account locality of access, as… MariaDB 5.5 with Hash Joins enabled is doing less Handler reads as compared to when the…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one… post is aimed at a new optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take a look briefly at what this enhancement actually is, and what…
Comment: Finding out largest tables on MySQL Server
April 24, 2012 By 24 Comments
…do the results of these …not shrink if data is deleted. However, what I’m wondering is if there …may be a good opportunity to run OPTIMIZE and thus reclaim some hard disk space?…mysql mysql 58G 2012-04-24 13:41 tablename.ibd On disk vs the information_schema query, there is around 9GB discrepancy. Does…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
…see your performance being worse. What should you do ? First if you followed MySQL upgrade best practices such as…may be wrong plan from optimizer standpoint and updating stats may cause old MySQL Version to get …wish to create a repeatable test case which does not use any sensitive data and file …
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…and generally keeping in touch with what the lead consultant does. We want two sets of…what MySQL instances are on the machine. It doesn’t do to just assume there’s a single instance in /var/lib/mysql…big gains. Schema, query, and index optimization Analyzing and optimizing a server’s table and index …
Post: Economics of Performance Optimization
March 13, 2008 By 9 Comments
…, requires even higher experience to do well and poses higher risks. …does not give you much benefit – you would just need another server a bit later. However if you have 100 MySQL…optimization. Same often applies to HA as higher scale applications tend to have higher cost of downtime. So now what…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…’re doing this with vanilla MySQL, you will need to aggregate your data. What you want to do is aggregate in ways that optimize the…/XtraDB tables… Optimize For I/O It is pretty much inevitable: if you do this kind of data processing in MySQL, you’re… hard they have to work on I/O capacity. What does this have to do with InnoDB? Data clustering. InnoDB’s primary…
Post: Possible optimization for sort_merge and UNION ORDER BY LIMIT
September 18, 2007 By 10 Comments
… ORDER BY ORD LIMIT 10 to individual queries. What if we do int manually ? mysql> explain (select * from utest where c1=5 order… it is great optimization which you need to do manuall for the time being. What is also interesting is the fact MySQL is unable… data. Another possible optimizer improvement to do. P.S This post is inspired by Does MySQL Optimize UNION with LIMIT clause topic on our MySQL Forums.
