Ruby’s DBI or ActiveRecord
Sunday, April 9th, 2006While creating a small CGI web application in Ruby the question came up about how much slower ActiveRecord is than DBI. Considering that ActiveRecord is initialized each time the CGI runs the performance hit could be significant.
So why not use Rails instead? The server that I am running the application on has limited resources. Rails is reported to need about 20 MB of memory and the node I have is already paging out memory to disk.
To emulate the webserver getting hit repeatedly with connections I created a connect_dbi.rb and and connect_ar.rb that insert the same row into a Tests database table. The ActiveRecord test also has the model file test.rb
The test was run using a PostGreSQL database on Ubuntu 5.10 with Ruby 1.8.4. The table was truncated between tests. I just wanted to get an idea of the performance difference between ActiveRecord and DBI. So this isn’t the strictest performance test but does provide an idea of the magnitude of difference.