Which version to use when upgrading from MySQL 4.1?


I’ve been following Percona’s developments closely for years and am impressed with the products.

My machine has an AMD dualcore 185 with 2GB of RAM. Linux 2.6.9. It also has PHP and Lighttpd running on it. I’m still using MySQL 4.1.22 with MyISAM tables and the database is about 3.7GB in 67 tables. The tables with text data have been broken up so that the main meta data are in fixed tables and the text is mostly cached so those tables aren’t read from much. The DB is heavy on the read side with a lot of composite primary keys. Also, backups are made nightly using mysqlhotbackup (which locks the DB for about 10min).

My question: Is it worth it to upgrade to Percona’s 5.5? I’m concerned that the new version will use up more RAM or increase IO, which would increase the load on the sever with no real benefit.

Some details from my.cnf:
thread-cache-size = 10
query-cache-min-res-unit = 2048

Any thoughts on the direction to take?


Because you use MyISAM, I assume you do not mind losing data and you do not care about data integrity. A conversion to InnoDB will make MySQL use more memory, especially for secondary indices because your primary key is large and it is stored for every leaf in a secondary index. You may benefit from page compression though.

Even if you keep running MyISAM, you may or may not benefit from an upgrade, but differences are likely to be small.

A real reason for an upgrade would be the bugfixes or the better performance metrics.

Right, losing a day’s worth of data or getting a few corrupt rows isn’t a big deal. It’s never happened yet. A few tables have over 3million rows.