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 …

One of the most asked questions is how to setup MySQL replication. The MySQL Reference Manual provides a good Replication How To as a starting guide on MySQL Replication 101.

MySQL replication has many uses including read scalability, backups, failover, online maintenance, upgrade testing and verification, software upgrades, alternative data or structure for performance queries and even benchmarking to name the popular uses.

When reviewing an installation of MySQL replication I use the following as part of my checklist of steps used for confirming your replication environment is operational.

Master Variables

• server-id – Replication will not work without this correctly set and unique
• log-bin – Pre-requisite for working replication
• log-bin-index
• max_binlog_size
…

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 …

As a frequent traveler for my MySQL consulting (last 4 weeks were Sydney, San Francisco, New York and Vancouver), I like to keep abreast of any local tech event that includes MySQL that I may be able to attend.

Now there is a consolidated location that you can use, the Open Source Events Calendar. Kudos to the MySQL Community team members Lenz Grimmer and Giuseppe Maxia who have put this together.

We need your help. If you have a local event, please submit your event request. This projects needs the support of all.

You will also find valuable conference information including dates for close of proposals. A great tool for scheduling your upcoming conference year.

I’ve always believed that the MySQL Information_schema.tables.table_rows figure for Innodb tables to be while approximate, approximately accurate.

Today I found that the figures varied on one table from 10x to 100x wrong.

Before performing an ALTER I always verify sizes for reference.

+---------+------------+--------+------------+------------+----------------+------------+------------+-----------+------------+
| table_s | table_name | engine | row_format | table_rows | avg_row_length | total_mb   | data_mb    | index_mb  | today      |
+---------+------------+--------+------------+------------+----------------+------------+------------+-----------+------------+
| XXXXX   | s_a        | InnoDB | Compact    |     208993 |           7475 |  1491.5312 |  1490.0156 |    1.5156 | 2009-09-09 |

mysql> alter table s_a modify col VARCHAR(255);
Query OK, 23471 rows affected (4 min 26.23 sec)

After

 …

MySQL provides a level of statistics for your INSERT, UPDATE, DELETE, REPLACE Data Manipulation Language (DML) commands using the STATUS output of various Com_ variables, however it is per server stats. I would like per table stats.

You can achieve this with tools such as MySQL Proxy and mk-query-digest, however there is actually a very simple solution that requires no additional tools.
The following 1 line Linux command (reformatted for ease of reading) gave me exactly what I wanted, and it had ZERO impact on the database.

$ mysqlbinlog /path/to/mysql-bin.000999 |  \
   grep -i -e "^update" -e "^insert" -e "^delete" -e "^replace" -e "^alter"  | \
   cut -c1-100 | tr '[A-Z]' '[a-z]' |  \
   sed -e "s/\t/ /g;s/\`//g;s/(.*$//;s/ set .*$//;s/ as .*$//" | sed -e "s/ where .*$//" |  \
   sort | uniq -c | sort -nr  

  33389 update e_acc
  17680 insert into r_b
  17680 insert into e_rec
  14332 insert into rcv_c
  13543 update e_rec
  10805 …

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 …