July 29, 2014

Using Multiple Key Caches for MyISAM Scalability

I have written before – MyISAM Does Not Scale, or it does quite well – two main things stopping you is table locks and global mutex on the KeyCache. Table Locks are not the issue for Read Only workload and write intensive workloads can be dealt with by using with many tables but Key Cache […]

How Percona does a MySQL Performance Audit

Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This […]

ANALYZE: MyISAM vs Innodb

Following up on my Previous Post I decided to do little test to see how accurate stats we can get for for Index Stats created by ANALYZE TABLE for MyISAM and Innodb. But before we go into that I wanted to highlight about using ANALYZE TABLE in production as some people seems to be thinking […]

How adding another table to JOIN can improve performance ?

JOINs are expensive and it most typical the fewer tables (for the same database) you join the better performance you will get. As for any rules there are however exceptions The one I’m speaking about comes from the issue with MySQL optimizer stopping using further index key parts as soon as there is a range […]

MyISAM Scalability and Innodb, Falcon Benchmarks

We many times wrote about InnoDB scalability problems, this time We are faced with one for MyISAM tables. We saw that several times in synthetic benchmarks but never in production, that’s why we did not escalate MyISAM scalability question. This time working on the customer system we figured out that box with 1 CPU Core […]

Using GROUP BY WITH ROLLUP for Reporting Performance Optimization

Quite typical query for reporting applications is to find top X values. If you analyze Web Site logs you would look at most popular web pages or search engine keywords which bring you most of the traffic. If you’re looking at ecommerce reporting you may be interested in best selling product or top sales people. […]

MySQL VIEW as performance troublemaker

I start to see applications being built utilizing VIEWs functionality which appeared in MySQL 5.0 and quite frequently VIEWs are used to help in writing the queries – to keep queries simple without really thinking how it affects server performance. Even worse than that – looking at the short table which just gets single row […]

Performance impact of complex queries

What is often underestimated is impact of MySQL Performance by complex queries on large data sets(ie some large aggregate queries) and batch jobs. It is not rare to see queries which were taking milliseconds to stall for few seconds, especially in certain OS configurations, and on low profile servers (ie having only one disk drive) […]

InnoDB vs MyISAM vs Falcon benchmarks – part 1

Several days ago MySQL AB made new storage engine Falcon available for wide auditory. We cannot miss this event and executed several benchmarks to see how Falcon performs in comparison to InnoDB and MyISAM. The second goal of benchmark was a popular myth that MyISAM is faster than InnoDB in reads, as InnoDB is transactional, […]

Cache Performance Comparison

Jay Pipes continues cache experiements and has compared performance of MySQL Query Cache and File Cache. Jay uses Apache Benchmark to compare full full stack, cached or not which is realistic but could draw missleading picture as contribution of different components may be different depending on your unique applications. For example for application containing a […]