Any indexes to be created when using pg_search_scope for searching within a single model

[Bharat]

Thanks for creating this wonderful gem.  It make leveraging full-text search using Postgres super easy.  It is working great in my application.

I have a doubt though.  All my full-text searches target a single model and are against multi-columns.  Do I have to create any specialized

indexes as Ryan Bates does in his screencast on Postgres full text search?

http://railscasts.com/episodes/343-full-text-search-in-postgresql?view=asciicast

Here is a specific example:

I have a scenario model which has the following code related to the Postgres full-text search using the pg_search gem:

class Scenario < ActiveRecord::Base

  ...

    include PgSearch

  pg_search_scope :search, :against => [:name, :compute_ngls],

    :using => { :tsearch => {:dictionary => "english"} }

  def self.text_search(query)

    if query.present?

      search(sanitize(query))

    else

      scoped

    end

             end

    ...

end

The call to the text_search method is as follow:

      scenarios = scenarios.text_search(params[:sSearch])

 

I only have regular btree indexes on certain columns, e.g., :name for instance.  I do not have gin or gist indexes.  My question is: should I explicitly create these indexes?  If yes then which kind and on which columns?  Can you please give me the syntax for creating these indexes?

Thanks.

Bharat