This is the third blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is targeted at the join related optimizations introduced in the optimizer. These optimizations are available in both MySQL 5.6 and MariaDB 5.5, and MariaDB 5.5 [...]
MySQL caching methods and tips
April 4, 2011 By 5 Comments
“The least expensive query is the query you never run.” Data access is expensive for your application. It often requires CPU, network and disk access, all of which can take a lot of time. Using less computing resources, particularly in the cloud, results in decreased overall operational costs, so caches provide real value by avoiding [...]
High Rate insertion with MySQL and Innodb
January 7, 2011 By 17 Comments
I again work with the system which needs high insertion rate for data which generally fits in memory. Last time I worked with similar system it used MyISAM and the system was built using multiple tables. Using multiple key caches was the good solution at that time and we could get over 200K of inserts/sec. [...]
Why you should ignore MySQL’s key cache hit ratio
February 28, 2010 By 28 Comments
I have not caused a fist fight in a while, so it’s time to take off the gloves. I claim that somewhere around of 99% of advice about tuning MySQL’s key cache hit ratio is wrong, even when you hear it from experts. There are two major problems with the key buffer hit ratio, and [...]
Crashes while using MyISAM with multiple key caches
July 18, 2009 By Leave a Comment
Over last couple of years I have ran into random MySQL crashes in production when multiple key caches were used. Unfortunately this never was frequent or critical enough issue so I could spend time creating repeatable test case and search of the bug in the MySQL database did not find anything. Recently we had this [...]
Getting annoyed with MyISAM multiple key caches.
May 1, 2009 By 11 Comments
As I’ve wrote few times using multiple key caches is a great way to get CPU scalability if you’re using MyISAM. It is however very annoying – this feature really looks half baked to me. The problem with multiple key caches and mapping of tables to the different files is – there is no way [...]
Using Multiple Key Caches for MyISAM Scalability
November 26, 2008 By 8 Comments
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 [...]
Beware of MyISAM Key Cache mutex contention
August 12, 2008 By 10 Comments
Today I was working with the client loading data to MyISAM tables at very high rate. Hundreds of millions rows are loaded daily into single MySQL instance with bursts up to 100K of records/sec which need to be inserted (in the table with few indexes). It was good not all records had to go to [...]
MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
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 [...]
Cache Performance Comparison
August 9, 2006 By 74 Comments
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 [...]
