instance method indexes

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 636
      def indexes(table_name, name = nil)
         schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',')
         result = query(<<-SQL, name)
           SELECT distinct i.relname, d.indisunique, a.attname
             FROM pg_class t, pg_class i, pg_index d, pg_attribute a
           WHERE i.relkind = 'i'
             AND d.indexrelid = i.oid
             AND d.indisprimary = 'f'
             AND t.oid = d.indrelid
             AND t.relname = '#{table_name}'
             AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname IN (#{schemas}) )
             AND a.attrelid = t.oid
             AND ( d.indkey[0]=a.attnum OR d.indkey[1]=a.attnum
                OR d.indkey[2]=a.attnum OR d.indkey[3]=a.attnum
                OR d.indkey[4]=a.attnum OR d.indkey[5]=a.attnum
                OR d.indkey[6]=a.attnum OR d.indkey[7]=a.attnum
                OR d.indkey[8]=a.attnum OR d.indkey[9]=a.attnum )
          ORDER BY i.relname
        SQL

        current_index = nil
        indexes = []

        result.each do |row|
          if current_index != row[0]
            indexes << IndexDefinition.new(table_name, row[0], row[1] == "t", [])
            current_index = row[0]
          end

          indexes.last.columns << row[2]
        end

        indexes
      end