Keep a table out of schema.rb during migrations

Question

As a follow-on to an earlier question about not reloading a huge, persistent table when I run my tests, I need to keep this table out of schema.rb when I run my migrations.

Answer 1

Turns out there's an option for just this situation!

I found it in activerecord-2.3.4/lib/active_record/schema_dumper.rb:

##
# :singleton-method:
# A list of tables which should not be dumped to the schema. 
# Acceptable values are strings as well as regexp.
# This setting is only used if ActiveRecord::Base.schema_format == :ruby
cattr_accessor :ignore_tables 
@@ignore_tables = []

So all I had to do was stick this at the end of environment.rb:

ActiveRecord::SchemaDumper.ignore_tables = ["table_name"]

The ignore_tables option will accept regular expressions. For example, to ignore all tables starting with "MS":

ActiveRecord::SchemaDumper.ignore_tables = [/^MS/]