Many software developers find they need to store hierarchical data, such as threaded comments, personnel org charts, or nested bill-of-materials. Sometimes it’s tricky to do this in SQL and still run efficient queries against the data. I’ll be presenting a webinar for Percona on February 28 at 9am PST. I’ll describe several solutions for storing [...]
MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
This is the third in a series on what’s seriously limiting MySQL in core use cases (links: part 1, 2, 3). This post is about the way MySQL handles connections, allocating one thread per connection to the server.
On Good Instrumentation
May 31, 2010 By 1 Comment
In so many cases troubleshooting applications I keep thinking how much more efficient things could be going if only there would be a good instrumentation available. Most of applications out there have very little code to help understand what is going on and if it is there it is frequently looking at some metrics which [...]
Goal driven performance optimization
December 22, 2008 By Leave a Comment
When your goal is to optimize application performance it is very important to understand what goal do you really have. If you do not have a good understanding of the goal your performance optimization effort may well still bring its results but you may waste a lot of time before you reach same results as [...]
How much space does empty Innodb table take ?
December 16, 2008 By 7 Comments
How much space would empty MyISAM table take ? Probably 8K for .frm file, 1KB for .MYI file and 0 for MYD file. .MYI file can be larger if you have many indexes. How much space will Innodb take:
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 patches, new builds
September 5, 2008 By 24 Comments
We made new patches, improved previous and want to announce new builds for 5.0.62, 5.0.67 and 5.1.26 versions. One of biggest changes we separated releases of 5.0 into two branches. First, just “-percona” release is more stable and contains only stable and proven on many installation patches. Second is “-percona-highperf” release, which contains experimental patches [...]
Apache PHP MySQL and Runaway Scripts
May 20, 2008 By 20 Comments
Sometimes due to programming error or due to very complex query you can get your PHP script running too long, well after user stopped waiting for the page to render and went browsing other sites. Looking at Server-Status I’ve seen scripts executing for hours sometimes which is obviously the problem – they take Apache Slot, [...]
MySQL 6.0 vs 5.1 in TPC-H queries
March 25, 2008 By 17 Comments
Last week I played with queries from TPC-H benchmarks, particularly comparing MySQL 6.0.4-alpha with 5.1. MySQL 6.0 is interesting here, as there is a lot of new changes in optimizer, which should affect execution plan of TPC-H queries. In reality only two queries (from 22) have significantly better execution time (about them in next posts), [...]
mk-query-digest, query comments and the query cache
I very much like the fact that MySQL allows you to embed comments into SQL statements. These comments are extremely convenient, because they are written into MySQL log files as part of the query. This includes the general log, the binary log and the slow query log. Maatkit includes tools which interact with these logs, [...]