tables_in_string

# File activerecord/lib/active_record/relation.rb, line 609
      def tables_in_string(string)
        return [] if string.blank?
        # always convert table names to downcase as in Oracle quoted table names are in uppercase
        # ignore raw_sql_ that is used by Oracle adapter as alias for limit/offset subqueries
        string.scan(/([a-zA-Z_][.\w]+).?\./).flatten.map(&:downcase).uniq - ["raw_sql_"]
      end