In the first part of this article I have showed how I align IO, now I want to share results of the benchmark that I have been running to see how much benefit can we get from a proper IO alignment on a 4-disk RAID1+0 with 64k stripe element. I haven’t been running any benchmarks [...]
FlashCache: more benchmarks
May 18, 2010 By 15 Comments
Previously I covered simple case with FlashCache, when data fits into cache partitions, now I am trying to test when data is bigger than cache. But before test setup let me address some concern (which I also had). Intel X25-M has a write cache which is not battery backuped, so there is suspect you may [...]
Should I buy a Fast SSD or more memory?
April 8, 2010 By 10 Comments
While a scale-out solution has traditionally been popular for MySQL, it’s interesting to see what room we now have to scale up – cheap memory, fast storage, better power efficiency. There certainly are a lot of options now – I’ve been meeting about a customer/week using Fusion-IO cards. One interesting choice I’ve seen people make [...]
table_cache negative scalability
November 16, 2009 By 23 Comments
Couple of months ago there was a post by FreshBooks on getting great performance improvements by lowering table_cache variable. So I decided to investigate what is really happening here. The “common sense” approach to tuning caches is to get them as large as you can if you have enough resources (such as memory). With MySQL [...]
How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
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 [...]
New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
As you likely have seen Sun has posted the new SpecJAppServer Results More information from Tom Daly can be found here These results are quite interesting for me as I worked on some of the previous SpecJAppServer Benchmarks several years ago while being employed by MySQL. These are great results, plus they can be relevant [...]
Development plans
September 8, 2008 By 5 Comments
We gathered together our ideas of MySQL improvements on this page http://www.percona.com/percona-lab/dev-plan.html and we are going to implement some of them. My favorite one is – make InnoDB files .ibd (one created with –innodb-file-per-table=1) movable from one server to another, however it is sort of challenging. Probably next one patch we want to integrate is [...]
Heikki Tuuri Innodb answers – Part I
October 26, 2007 By 19 Comments
Its almost a month since I promised Heikki Tuuri to answer Innodb Questions. Heikki is a busy man so I got answers to only some of the questions but as people still poking me about this I decided to publish the answers I have so far. Plus we may get some interesting follow up questions [...]
UNION vs UNION ALL Performance
October 5, 2007 By 15 Comments
When I was comparing performance of UNION vs MySQL 5.0 index merge algorithm Sinisa pointed out I should be using UNION ALL instead of simple UNION in my benchmarks, and he was right. Numbers would be different but it should not change general point of having optimization of moving LIMIT inside of union clause being [...]
Possible optimization for sort_merge and UNION ORDER BY LIMIT
September 18, 2007 By 10 Comments
Every so often you need to perform sort results retrieved from MySQL when your WHERE clause goes beyound col=const values which would allow MySQL to still use second portion of the index for the order by. Ranges as well as IN lists make this optimization impossible, not even speaking about index merge optimization. Lets look [...]
