The latest from the MySQL community

The EXPLAIN command is an important tool to review how a SQL query is executed and in this example includes what indexes are used.

By adding a covering index I ended up with the following EXPLAIN plan I was unable to explain. The end result was a boost in server performance which was the ultimate goal.

mysql> explain select max(md)  from e_r  where email = 'xxxx@gmail.com' and id = '36981';
+----+-------------+-------+------+---------------+------+---------+------+------+------------------------------+
| id | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra                        |
+----+-------------+-------+------+---------------+------+---------+------+------+------------------------------+
|  1 | SIMPLE      | NULL  | NULL | NULL          | NULL | NULL    | NULL | NULL | Select tables …

Recently I was working on a project which used Infobright as the database. The version tested was 3.1.1 both on OpenSolaris as well as Solaris 10. Infobright is like a column-oriented database engine for MySQL primarily targeted towards data warehouse, data mining type of project deployments.

While everything was working as expected, one thing we did notice that as number of concurrent connections tried to query against the database we noticed that queries deteriorated fast in the sense that not much parallel benefits were being squeezed from the machine. Now this sucks! (apparently sucks is now a technical term). It sucks because the server has definitely many  cores and typically each Infobright query still can at the max peg a core. So the expectation will be typically to atleast handle concurrent queries which is close to the number of cores  (figuratively speaking though …

Recently I was working on a project which used Infobright as the database. The version tested was 3.1.1 both on OpenSolaris as well as Solaris 10. Infobright is like a column-oriented database engine for MySQL primarily targeted towards data warehouse, data mining type of project deployments.

While everything was working as expected, one thing we did notice that as number of concurrent connections tried to query against the database we noticed that queries deteriorated fast in the sense that not much parallel benefits were being squeezed from the machine. Now this sucks! (apparently sucks is now a technical term). It sucks because the server has definitely many  cores and typically each Infobright query still can at the max peg a core. So the expectation will be typically to atleast handle concurrent queries which is close to the number of cores  (figuratively speaking though …

Recently I was working on a project which used Infobright as the database. The version tested was 3.1.1 both on OpenSolaris as well as Solaris 10. Infobright is like a column-oriented database engine for MySQL primarily targeted towards data warehouse, data mining type of project deployments.

While everything was working as expected, one thing we did notice that as number of concurrent connections tried to query against the database we noticed that queries deteriorated fast in the sense that not much parallel benefits were being squeezed from the machine. Now this sucks! (apparently sucks is now a technical term). It sucks because the server has definitely many  cores and typically each Infobright query still can at the max peg a core. So the expectation will be typically to atleast handle concurrent queries which is close to the number of cores  (figuratively speaking though …

While not a MySQL topic, as most of my readers view my MySQL Blog, my WordPress blog has been hacked? Has yours?

Like many, I’m sure you may have read about it like at Wordpress blogs under attack from hack attack but I was surprised when my custom permlinks did not work.

Being surprised I looked at Administrator accounts, and I found that there was one more number then being displayed in the list. I had to dig into the database to find the problem.

mysql> select * from wp_users where ID in (select user_id from wp_usermeta where meta_key = 'wp_capabilities' and meta_value like '%admin%');
+-----+-------------+------------------------------------+---------------+------------------------------+---------------------------+---------------------+---------------------+-------------+--------------+
| ID  | user_login  | user_pass                          | user_nicename | …

The summer break seems to be over and the event season is heating up again! There is a number of conferences and events coming up in the next months — here is a quick summary of the events that I plan to attend.

This Friday I will attend an event here in Hamburg: the "Silpion Sommerfest", organized by Silpion (a local IT solutions provider which is a partner of Sun Microsystems as well). I will be there to network and talk about MySQL.

This coming weekend (2009-09-12/2009-09-13), there will be the PHP Unconference here in Hamburg, Germany . It will consist of two days of Barcamp-style sessions about …

It's almost two weeks now since FrOSCon and the OpenSQL Camp subconference have taken place in Sankt Augustin, Germany — about time for a summary and update from my side!

First off, I would like to thank all of the participants and supporters, particularly my colleagues Regina Steyer and Iris Musiol for the perfect logistics and co-sponsoring as well as Uli Graef, Thorsten Frueauf, Matthias Schmidt, Alexander Rubin and Joerg Moellenkamp for manning the Sun booth and the help on site.

Another big Thank You goes out to my team mates …

In the past few weeks I've been implementing advanced search at Plaxo, working quite closely with Solr enterprise search server. Today, I saw this relatively detailed comparison between Solr and its main competitor Sphinx (full credit goes to StackOverflow user mausch who had been using Solr for the past 2 years). For those still confused, Solr and Sphinx are similar to MySQL FULLTEXT search, or for those even more confused, think Google (yeah, this is a bit of a stretch, I know).

Similarities

• Both Solr and Sphinx satisfy all of your requirements. They're fast and designed to index and search large bodies of data efficiently.
• Both have a long list of high-traffic sites …

I have several side projects when time permits and one is that of benchmarking various MySQL technologies (e.g. MySQL 5.0,5.1,5.4), variants (e.g. MariaDB, Drizzle) and storage engines (e.g. Tokutek, Innodb plugin) and even other products like Tokyo Cabinet which is gaining large implementations.

You have two options with benchmarks, the brute force approach such as Sysbench, TPC, sysbench, Juice Benchmark, iibench, mysqlslap, skyload. I prefer the realistic approach however these are always on client’s private data. What is first needed is better access to public data for benchmarks. I have compiled this list to date and I am seeking additional sources for reference.

• Feebase – Data is in clean loadable format
• IMDB – Not clean, but Roland Bouman is working on …

After the slow down due to vacation and warm weather we are ready for a series of educative Italian webinars on MySQL. Here is the list:

Semptember 10@10am CET - "Top 5 Tuning tips for MySQL"
Are your applications slow during peak times? Is the database running slowly? Do you find difficult to pinpoint performance problems? Then this webinar is for you!I will cover the top 5 tips to speed up your MySQL databases from a developer as well as DBA point of view.

October 8@10am CET - "Introduction to MySQL for Windows"
Do you know that MySQL is used extensively on Windows? Would you like to learn the tools that we provide?
Join this webinar! We will discuss the advantages of using MySQL on the …