Using MyISAM tables?

Jean-nicolas Jolivet wrote:

I was wondering if there were any drawbacks in using MyISAM tables instead of InnoDB? Main reason is that I have limited memory on my VPS and skipping innodb tables makes a considerable difference in memory usage.    You may want to try PostgreSQL then... When I started using a 64MB VPS I tried MySQL hoping it was lightweight compared to the more feature-rich PostgreSQL, I was disappointed.

I know that rails migration create InnoDB tables by default, I was wondering if there are any reasons for this or if I can just use MyISAM without noticing any difference on the coding end... ?    On the coding end, there's no difference, but : - transactions will not be used without any warning (the SQL will be executed but no rollback will ever happen in case of failure), - concurrent access to the DB will be slow (no row-level locking), should not be a problem on a memory constrained system though, - you will rely entirely on ActiverRecord validations to enforce foreign keys (there are race conditions that can corrupt your database instead of triggering an exception),