By goldentoque on

I am wanting to use civimail which requires mysql 5. Before upgrading the database, from mysql 4.1 I thought I would ask around to see if there was anything I should look out for, or if anyone had some sage advice for me?

Thanks,

Darren

⋅ Categories: Drupal 4.7.x

Comments

peterx’s picture

peterx commented

For anyone upgrading from 4.0 to 4.1 or 5.0, you change from mysql to mysqli. Drupal handles it but some other code does not.

5.0 introduces subqueries, which I like, but if you use subqueries in your modules, they will not work with 4.1 or 4.0. You might want to change all your sites to 5.0 before changing modules to use subqueries.

Subqueries can also change the way MySQL uses indexes, which can make a slow query faster or a fast query slower. The inner queries run first which means they should be the most selective and best indexed.

5.1 includes the Falcon engine which replaces Innodb. Transactions with less overhead and less locking. Drupal 6.0 can use transactions with Falcon.

petermoulding.com/web_architect

petermoulding.com/web_architect

mo6’s picture

mo6
he/him
Primary language Dutch
commented

"Starting with MySQL 4.1, all subquery forms and operations that the SQL standard requires are supported, as well as a few features that are MySQL-specific."

See: http://dev.mysql.com/doc/refman/5.0/en/subqueries.html

peterx’s picture

peterx commented

MySQL 5 changes the order in which it evaluates SQL. See http://drupal.org/node/110393 and read the two linked pages inside.

petermoulding.com/web_architect

petermoulding.com/web_architect