Earlier this week, Cédric blogged about how easy we can get confused between a covering index and a full index scan in the EXPLAIN output. While a covering index (seen with EXPLAIN as Extra: Using index) is a very interesting performance optimization, a full index scan (type: index) is according to the documentation the 2nd [...]
My previous poll got a great response so I thought I should continue these series. The question of the day today is How much data do your store in your largest MySQL instance ? I’m interested about single instance not the total amount of data you have in MySQL in your Sharded replicated environment. Feel [...]
MySQL 5.6.7 RC is there, so I decided to test how it performs in tpcc-mysql workload from both performance and stability standpoints. I can’t say that my experience was totally flawless, I bumped into two bugs: MySQL 5.6.7 locks itself on CREATE INDEX MySQL 5.6.7-rc crashed under tpcc-mysql workload But at the end, is not [...]
James Day just posted the great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are a lot of good changes and many defaults are now computed instead of hardcoded. Though some of changes are rather puzzling for me. Lets go over them: back_log = 50 + ( max_connections / [...]
Yesterday, over at my personal blog, I blogged about the impact of the MySQL slow query log. Since we’re working on Percona Server 5.6, I did wonder if this was a good opportunity to re-examine how we could provide slow query log type functionality to our users. The slow query log code inside the MySQL [...]
I continue my benchmarks of Intel SSD 910, previous time I compared it with Fusion-io ioDrive http://www.mysqlperformanceblog.com/2012/09/07/intel-ssd-910-in-tpcc-mysql-benchmark/. Now I want to test this card against RAID over spinning disks.
This is to continue my previous experiments on adaptive flushing in MySQL 5.6.6. Now I am running Ubuntu 12.04, which seems to provide a better throughput than previous system (CentOS 6.3), it also changes the profile of results. So, as previous I run tpcc-mysql 2500W, against MySQL 5.6.6 with innodb_buffer_pool_size 150GB, and now I vary [...]
I continue my benchmarks of Intel SSD 910, the raw IO results are available in my previous experiment. Now I want to test this card under MySQL workload to see if the card is suitable to use with MySQL. Benchmark date: Sep-2012 Benchmark goal: Test Intel SSD 910 under tpcc-mysql workload and compare with baseline [...]
As you may know, flushing in MySQL is an area of my interest, I wrote about it several times, i.e. http://www.mysqlperformanceblog.com/2011/09/18/disaster-mysql-5-5-flushing/ http://www.mysqlperformanceblog.com/2011/03/31/innodb-flushing-a-lot-of-memory-and-slow-disk/ http://www.mysqlperformanceblog.com/2011/01/03/mysql-5-5-8-in-search-of-stability/ In MySQL 5.6 there was implemented a new flushing logic, so I decided to check what do we have now.
I presented a webinar this week to give an overview of several Full Text Search solutions and compare their performance. Even if you missed the webinar, you can register for it, and you’ll be emailed a link to the recording. During my webinar, a number of attendees asked some good questions. Here are their questions and my [...]