Baron pointed to two really good articles recently by Brendan Gregg on Filesystem Latency (part1 / part2), that I too would recommend everybody read.

They rightly point out that trying to correlate IO statistics from tools such as iostat to a databases workload, especially when that database is on a shared resource, is fraught with complications – and further to that, not the full picture anyway, even on a dedicated system. Brendan points out that to get the full picture, you really need to be instrumenting your profiling at the read/write layer of the application …

So, as LinuxJedi so eloquently noted here, Rackspace and Drizzle are parting ways.  While they were kind enough to offer other opportunities with them, my preferences were similar to Andrew’s – to remain in the MySQL/Drizzle world.

I was fortunate enough that SkySQL had need of my services and am happy to announce that today marks my first day as a Senior QA Engineer with them.  I am very honored to join such a promising and skilled group and am very excited about the opportunities ahead.

My work will have me developing QA solutions (tests, code, whatever) for a wide variety of things.  Naturally, this includes SkySQL’s Reference Architecture …

Dear Kettlers,

A couple of years ago I wrote a post about key/value tables and how they can ruin the day of any honest person that wants to create BI solutions.  The obvious advice I gave back then was to not use those tables in the first place if you’re serious about a BI solution.  And if you have to, do some denormalization.

However, there are occasions where you need to query a source system and get some report going on them.  Let’s take a look at an example :

mysql> select * from person;
+----+-------+----------+
| id | name  | lastname |
+----+-------+----------+
|  1 | Lex   | Luthor   |
|  2 | Clark | Kent     |
|  3 | Lois  | Lane     |
+----+-------+----------+
3 rows in set (0.00 sec)

mysql> select * from person_attribute;
+----+-----------+---------------+------------+
| id | person_id | attr_key      | attr_value | …

The binary version for MySQL Cluster 7.1.13 has now been made available at http://www.mysql.com/downloads/cluster/

A description of all of the changes (fixes) that have gone into MySQL Cluster 7.1.13 (compared to 7.1.10) can be found in the official MySQL Cluster documentation for Cluster 7.1.13, 7.1.12 & 7.1.11.

So Vadim posted on the MySQL Performance Blog about poor benchmarks when running innodb compressed pages.  I ran some tests a few weeks ago and did not see the same results as him and checked into my previous tests and compared them to his #’s.  In a round about way verifying his thoughts on Mutex contention I found that increasing the BP sized with compressed data decreases the transactional throughput. The test was run with an uncomressed data set size of 6GB, 3.1GB compressed read-only.

Facebook recently updated their PHP-SDK to version 3.0. This is a major change. So I decided to update some of my facebook related tutorials with updated code.

At first I want to tell you that, this post is the updated version of my popular post Graph API & IFrame Base Facebook Application Development . So if you never saw that tutorial I request you to visit that and learn the basic things specially facebook application setup. Also on that post I mentioned some important things regarding iframe, so in this post I’ll not mention them again.

So in this updated post we will learn:

1. How …

This week we talk about time formats and time zones in MySQL - including how changing the system time changes TIMESTAMP values but not DATETIME values. We also talk about how to handle and store microseconds in MySQL.

From the MySQL manual:
date and time types
TIMESTAMP properties and how it is stored in UTC transparently in the database
ALLOW_INVALID_DATES sql_mode

read more

Another medley of database blogs under the famous banner of Log Buffer is in your virtual hands. This edition of Log Buffer, the Log Buffer #221 puts spotlight on the fresh and cool blogs from Oracle, MySQL and SQL Server arena.

Enjoy !!!

Oracle:

Martin is playing around with the Grid Infrastructure 11.2.0.2 PSU 2 and found an interesting note on My Oracle Support regarding the Patch Set Update.

Jonathan Lewis has found another gem as an answer to a question posted on OTN forums regarding the …

We all know that Kurt von Finck is going to give a talk at Percona Live NYC happening May 26 2011. If you want to attend we’ve got three tickets to give away (worth USD$249 each).

This should be the easiest contest ever to enter and win. Just go to the Knowledgebase, create an account and write one new article, longer than 2 paragraphs. Once you’re done, send a quick email to community@montyprogram.com with a link to the article, and if there is no duplicate content already on the Knowledgebase, you’ll get your ticket to Percona Live NYC.

Good luck!

Contest ends May 24 2011, noon, UTC+0.

I have just upgraded the xtrabackup bazaar code repositories to the 2a format. This means that bzr 1.16 is required to access the source code repositories now.

If you get an error like the one below when working with a local branch, you’ll need to run “bzr upgrade” in it (see below for example). For branches on launchpad, you can use the web UI and hit the “upgrade branch” button.

stewart@willster:~/src/percona-xtrabackup$ bzr pull
Using saved parent location: bzr+ssh://bazaar.launchpad.net/%2Bbranch/percona-xtrabackup/
Doing on-the-fly conversion from RemoteRepositoryFormat(_network_name='Bazaar repository format 2a (needs bzr 1.16 or later)\n') to RepositoryFormatKnitPack1().
This may take some time. Upgrade the repositories to the same format for better performance.
bzr: ERROR: KnitPackRepository('file:///home/stewart/src/percona-xtrabackup/.bzr/repository/')
is not compatible with …