pg_trgm gin postgre

add_pg_trgm_extension_to_db.rb

class AddPgTrgmExtensionToDb < ActiveRecord::Migration[5.0]
  # def change
  #   # execute "remove extension pg_trgm;"
  #   execute "create extension IF NOT EXISTS pg_trgm;"
  #   execute "CREATE EXTENSION IF NOT EXISTS btree_gin;"
  #
  #   remove_index :words, :word
  #   add_index :words, :word, using: :btree_gin
  # end
  def up
    execute "create extension IF NOT EXISTS pg_trgm;"
    execute "CREATE EXTENSION IF NOT EXISTS btree_gin;"

    remove_index :words, :word if index_exists?(:words, :word)
    add_index :words, :word, using: :gin
  end
  def down
    execute "drop extension IF EXISTS pg_trgm;"
    execute "drop EXTENSION IF EXISTS btree_gin;"

    remove_index :words, :word if index_exists?(:words, :word)
    # add_index :words, :word, using: :btree_gin
  end
end