We haven’t had a MySQL University session in a while (a semi-spring break?), but tomorrow’s session (May 8) should be real interesting. MySQL Cluster developer, Stewart Smith, will host a session titled Getting Started Using NDB. It will happen on May 8, at 13:00 UTC.

One of the most common queries I receive is from people wanting to install or get started with NDB usage (ok, strictly speaking, they want to “cluster” MySQL, and I’m happy Stewart is using the word “NDB” which refers to the storage engine). All in all, it should be a great session, so I encourage you to join in the festivities.

Managing database change is an incredibly important discipline that very few database professionals overtly talk or worry about until they're in the thick of things with a particular database - moving it from development to production, making changes to a newly installed production database, or implementing an updated version of the database (new tables, modifications to existing objects, etc.) in a SaaS application. It's at that point where change management becomes very important because if you don't do things right the first time, you can make a royal mess of things and even (in a small number of cases) reach the point of no return where you've completely torched your database.

A

Kaj tried to explain MySQL's "new" policy of offering closed extensions to its 100 percent open-source core (New? MySQL Monitor has been commercial-only since 2005 or so, as Marten Mickos recently reminded me), but Kaj's clarification clouded things more than it cleared them, such that wild throngs crowded the streets to celebrate their apparent success in browbeating MySQL into giving them all of its software for free, forever.

Put simply, Kaj indicated that one announced closed extension would now be open source, but said nothing about other potential closed extensions. People missed the point (which was not hard given the post's (correct) emphasis on all the open source that MySQL does and will do).

It …

Brian Moon suggest that community provided example my.cnf files would be a great thing to have on MySQLforge in this recent post: http://doughboy.wordpress.com/2008/05/06/example-mycnf-files/

I pulled out the "innodb heavy" config sample file and modified it with the standard settings that I typically start with when setting up a new InnoDB master. I've also modified the comments in the file a bit and have added some of my own too. I removed the sample slave configuration parameters (master-host, etc) because you should be using 'CHANGE MASTER TO'.

He suggested tagging such files with a 'mycnf' tag and very kindly tagged mine after I posted it :)

Feel free to share yours too and please feel free to make any comments about my configuration choices.

You can find it here (along with any other mycnf …

This is a great little sql statement that packs a nice punch for the number crunchers out there...A disclaimer first: make sure you don't do this on a live OLTP table with millions of rows unless you want your customers to wait. Thus, run it on your slave :).Onto business...The Request"I need to know the number of people who made one purchase, two purchases, three purchases, and so on. Right

I was cruising the MySQL Forge Worklog when I came across the idea of Time Delayed Replication. I had never considered the benefits of deliberately keeping a slave server behind a master.

Kristian Koehntopp gives a good example:

Kristian Koehntopp writes:

TDS: Time delayed SQL_THREAD (Have a replication slave that is always
lagging 30 minutes behind).

Currently, replication is a rolling recovery: To set up replication you
restore from a full dump with a binlog position. You then continously
download binlog and roll forward. In case of a master crash a slave is a
readily recovered instance (as opposed to a backup, which still has to be
restored).

This protects against crashes, but not against oopses.

A time delayed slave (TDS) is a nice protection against oopses.

Sugar on …

Well, it has been almost a month.  I know I am late to the blogosphere on my thoughts.  Just been busy.

Again this year, the Phorum team was invited to be a part of the DotOrg Pavilion.  What is that?  Basically they just give expo floor space to open source projects.  It is cool.  We had a great location this year.  We were right next to the area where they served food and drinks during the breaks.  We had lots of traffic and met some of our power users.  IMVU.com is getting 1.5 million messages per month in their Phorum install.  They did have to customize it to fit into their sharding.  But, that is expected.  A guy (didn't catch his name) from Innobase came by and told us that they just launced InnoDB support forums on their site using Phorum.  Cool.  So now …

I've been doing a lot of batch updates on one of my databases at home recently. show processlist says something like this:

mysql> show processlist;
+-------+------+---------------+--------------+---------+-------+----------+------------------------------------------+
| Id    | User | Host          | db           | Command | Time  | State    | Info                                     |
+-------+------+---------------+--------------+---------+-------+----------+------------------------------------------|
| 18354 | root | maui:37403    | smtp_servers | Query   | 57234 | Updating | update ips_218 set reverse_lookup = null |
| 22286 | root | maui:37348    | smtp_servers | Query   | 38103 | Updating | update ips_80 set reverse_lookup = null, |
| 22851 | root | maui:54982    | smtp_servers | Query   | 34091 | Updating | update ips_19 set reverse_lookup = null, | 
| 23351 | root | molokai:58232 | smtp_servers | Sleep   |    57 | …

Well, it has been almost a month.  I know I am late to the blogosphere on my thoughts.  Just been busy.

Again this year, the Phorum team was invited to be a part of the DotOrg Pavilion.  What is that?  Basically they just give expo floor space to open source projects.  It is cool.  We had a great location this year.  We were right next to the area where they served food and drinks during the breaks.  We had lots of traffic and met some of our power users.  IMVU.com is getting 1.5 million messages per month in their Phorum install.  They did have to customize it to fit into their sharding.  But, that is expected.  A guy (didn’t catch his name) from Innobase came by and told us that they just launced InnoDB support forums on their site using Phorum.  …