Recently, I found myself involved in the migration of a large read-only InnoDB database to MyISAM (eventually packed). The only issue was that for one of the table, we were talking of 5 TB of data, 23B rows. Not small… I calculated that with something like insert into MyISAM_table… select * from Innodb_table… would take [...]
Percona Live MySQL Conference & Expo Was A Great Event
April 17, 2012 By 2 Comments
Thanks to all of our sponsors, speakers, speaker selection committee, event staff, and especially the attendees for making last week’s conference a resounding success. With over a thousand people, the event made a good comeback after last year’s event, but more importantly, the mood was strongly optimistic. I think a lot of people arrived with [...]
How is join_buffer_size allocated?
July 5, 2010 By 9 Comments
When examining MySQL configuration, we quite often want to know how various buffer sizes are used. This matters because some buffers (sort_buffer_size for example) are allocated to their full size immediately as soon as they are needed, but others are effectively a “max size” and the corresponding buffers are allocated only as big as needed [...]
ANALYZE: MyISAM vs Innodb
September 3, 2008 By 9 Comments
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 [...]
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 [...]
Innodb Performance Optimization Basics
November 1, 2007 By 75 Comments
Interviewing people for our Job Openings I like to ask them a basic question – if you have a server with 16GB of RAM which will be dedicated for MySQL with large Innodb database using typical Web workload what settings you would adjust and interestingly enough most people fail to come up with anything reasonable. [...]
Using CHAR keys for joins, how much is the overhead ?
June 18, 2007 By 18 Comments
I prefer to use Integers for joins whenever possible and today I worked with client which used character keys, in my opinion without a big need. I told them this is suboptimal but was challenged with rightful question about the difference. I did not know so I decided to benchmark. The results below are for [...]
Using MyISAM in production
June 17, 2006 By 36 Comments
There were recently number of posts about MyISAM, for example Arjen wrote pretty nice article about MyISAM features so I thought I would share my own view on using MyISAM in production. For me it is not only about table locks. Table locks is only one of MyISAM limitations you need to consider using it [...]
Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
If you’ve been reading enough database related forums, mailing lists or blogs you probably heard complains about MySQL being unable to handle more than 1.000.000 (or select any other number) rows by some of the users. On other hand it is well known with customers like Google, Yahoo, LiveJournal,Technocarati MySQL has installations with many billions [...]
To pack or not to pack – MyISAM Key compression
May 13, 2006 By 4 Comments
MyISAM storage engine has key compression which makes its indexes much smaller, allowing better fit in caches and so improving performance dramatically. Actually packed indexes not a bit longer rows is frequent reason of MyISAM performing better than Innodb. In this article I’ll get in a bit more details about packed keys and performance implications [...]
