# Using MyISAM tables? **URL:** \ **Category:** Rails\ **Created:** [November 12, 2007, 10:33pm UTC](https://www.ruby-forum.com/t/using-myisam-tables/120007 "2007-11-12T22:33:18Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\ **Post date:** [November 12, 2007, 10:33pm UTC](https://www.ruby-forum.com/t/using-myisam-tables/120007/1 "2007-11-12T22:33:18Z")
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. 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… ? Thank you! ---
**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\ **Post date:** [November 12, 2007, 10:37pm UTC](https://www.ruby-forum.com/t/using-myisam-tables/120007/2 "2007-11-12T22:37:27Z")
On 12 Nov 2007, at 21:33, Jean-nicolas Jolivet wrote: > without noticing any difference on the coding end… ? > No foreign keys, no transactions, no row level locks etc… Fred ---
**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\ **Post date:** [November 12, 2007, 10:48pm UTC](https://www.ruby-forum.com/t/using-myisam-tables/120007/3 "2007-11-12T22:48:32Z")
Frederick C. wrote: > On 12 Nov 2007, at 21:33, Jean-nicolas Jolivet wrote: > > > without noticing any difference on the coding end… ? > > No foreign keys, no transactions, no row level locks etc… > > Fred Gotcha. But does no foreign key means that model relations won’t work?? (I.e. if I have a User table with a address\_id field…and an Address table, with a has\_one/belongs\_to relation…can I still use User.address to access his address info from the Address table?) ---
**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\ **Post date:** [November 12, 2007, 10:51pm UTC](https://www.ruby-forum.com/t/using-myisam-tables/120007/4 "2007-11-12T22:51:29Z")
No, it just means you can’t enforce data integrity at the db layer and will have to rely 100% on your models to enforce it. -Bill Jean-nicolas Jolivet wrote: > > > > Gotcha. But does no foreign key means that model relations won’t work?? > > (I.e. if I have a User table with a address\_id field…and an Address > table, with a has\_one/belongs\_to relation…can I still use User.address > to access his address info from the Address table?) – Sincerely, William P. ---
**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\ **Post date:** [November 12, 2007, 11:14pm UTC](https://www.ruby-forum.com/t/using-myisam-tables/120007/5 "2007-11-12T23:14:43Z")
Thank you all for the helpful replies! Exactly what I wanted to know! ---
**Author:** ![silvertab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/22d042/32.png) [@silvertab](https://www.ruby-forum.com/u/silvertab)\ **Post date:** [November 12, 2007, 10:52pm UTC](https://www.ruby-forum.com/t/using-myisam-tables/120007/6 "2007-11-12T22:52:39Z")
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), Lionel