# File lib/dbd_pg/Pg.rb, line 530
        def __blob_open(oid, mode=PGlarge::INV_READ)
          start_transaction unless @in_transaction
          @connection.lo_open(oid.to_i, mode)
          #if @attr['AutoCommit']
          #  _exec("COMMIT")
          #  @in_transaction = false
          #end
        rescue PGError => err
          raise DBI::DatabaseError.new(err.message) 
        end