rails/rails — pull request #14324 by jonatack (2014-03-08 10:37:30+00:00)
Title: Register PostgreSQL citext type to prevent "unknown OID" warnings

on citext columns.

Citext is a PostgreSQL data type for case-insensitive character strings.

To use it in a Rails application, add the `citext` extension in a migration:

````
class AddCitextExtension < ActiveRecord::Migration
def up
execute ‘CREATE EXTENSION IF NOT EXISTS citext;’
add_column :users, :search_field, 'citext'
end

def down
remove_column :users, :search_field, 'citext'
execute ‘DROP EXTENSION IF EXISTS citext CASCADE;’
end
end
````