Today I’m working on integrate the Percona toolkit (instead of maatkit) in my own tools and I’m playing with pt-query-digest and pt-query-advisor.
These tools can be very interesting to identify some queries from established rules.
The  –review option is available for two of them and helps me to store a sample of each class of query and match them with an advice.

The rules (or advices) are available in the pt-query-advisor documentation and let you identify various problems such as queries with an argument with leading wildcard or with a table joined twice, for example.
There are 3 types of rules : note, …

Nice one ... thank you :)

Join me Wednesday for a free webinar on using the new Percona Toolkit v2.0.3 to verify replication integrity. If you’re not familiar with this topic, it’s one of those must-do things that no one officially tells you is necessary with MySQL. The new tools in Percona Toolkit 2.0.3 make it much easier and less complicated – and safer – than before. Well worth an hour of your time.

If you're in the City of Angles this week, be sure to stop by the Southern California Linux Expo (SCALE) - the largest annual Linux, Open-Source, and Free Software conference held in Los Angeles.  Join SkySQL and its strategic partner, Monty Program, January 20-22, at the Hilton Los Angeles Airport hotel. Stop by our booth, #65, and meet our team. As well, don't miss our talks on MySQL & MariaDB:

• The MySQL Storage Engines Landscape - Colin Charles, Monty Program, Friday, 1/20, 11:30AM

• A Closer Look at MySQL Cluster:  An Architectural Overview - Max Mether, SkySQL, Friday, 1/20, 4:00PM

• MariaDB:  The New M in Lamp - Colin Charles, Monty Program, Friday, 1/20, 5:00PM

If you haven't …

The best way to run pt-query-digest is by making absolutely sure it is not running on any server that is even slightly important to production.

I recently had a case where pt-query-digest took up all the memory and swap on a (linux) development server. I think the reason was that the slow log had blob data in it.
Even though it wasn't a production server, it managed to upset some people.


So I:

1. Installed strawberry perl on my windows computer
2. Downloaded the gzip'd slow log file (using WinSCP)
3. Unzip'd it
4. Saved percon.com/get/pt-query-digest to a .pl file on my laptop
5. Went …

Installing Apache2 With PHP5 And MySQL Support On Fedora 16 (LAMP)

LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on a Fedora 16 server with PHP5 support (mod_php) and MySQL support.

In an ideal world, you should never need to use optimizer hints. In the real world, hints are necessary. We needed hints even before we’ve made a release. The first requests came from our Quality engineer who complained about it being difficult to hit particular join orders while using a particular subquery strategy.

So, why not add the needed hints? MySQL already has the STRAIGHT_JOIN and FORCE INDEX, you can add more as required. The problem is that once you have transformations that change the query to be far enough from the original SQL, you don’t have a “natural” place or syntax for hints anymore.

For example, if you have a join

SELECT ... FROM table1, table2, table3 WHERE ....

and want a join order of (table2, table3, table1), you can write it as

SELECT ... FROM table2 STRAIGHT_JOIN table3 STRAIGHT_JOIN table1

and that gives …

MySQL Day at SCALE is just a few days away. I will be giving a replication session that covers the concept, different configurations and then goes into the MySQL 5.6 Features for Replication as well. To name a few: Slave tables for replication, Replication Checksums, Time Delayed Replication (my favorite) and Optimized Row Based Replication. The 5.6 Features will include examples for setup, as all features tested with the latest DMR.

I look forward to seeing everyone.

I checked in some architectural changes to Mondrian's cache this week.
First the executive summary:
1. Mondrian should do the same thing as it did before, but scale up better to more concurrent queries and more cores.
2. Since this is a fairly significant change in the architecture, I'd appreciate if you kicked the tires, to make sure I didn't break anything.
Now the longer version.
Since we introduced external caches in Mondrian 3.3, we were aware that we were putting a strain on the caching architecture. The caching architecture has needed modernization for a while, but external caches made it worse. First, a call to an external cache can take a significant amount of time: depending on the cache, it might do a network I/O, and so take several orders of magnitude longer than a memory access. Second, we …

As a consultant I often use the MySQL Reference Manual to provide additional information for clients. I am very happy to recognize the quality of the content in the MySQL documentation, but why is the searching of the manual so, so bad?

While reading the General Security Issues section of the MySQL 5.5 manual, I performed a search for “CREATE USER”. I was not asking for anything abstract, this is an actual SQL command. I was rather horrified to find that the results could not even list the appropriate manual page in the first page of results.

I am not an expert in full-text search, however it does not take a rocket scientist to realize that a SQL keyword, the title of a page, in the language of the current page (English) and the current version of the Manual (5.5) should be …