                         if value[0] == '-'
                             value = value.slice(1) + " DESC "
                         r.order_by = value
+                    when 'heartbeat'
+                        # not implemented
+                        @_dbg("_query_parse_options")("TODO/WARNING -- ignoring heartbeat option!")
                     when 'delete'
-                        # ignore here - is parsed elsewhere
+                        # ignore delete here - is parsed elsewhere
                     else
                         r.err = "unknown option '#{name}'"
         return r

        else
            # increment before successfully making get_query to prevent huge bursts causing trouble!
            cnt[client_name] += 1
        @_dbg("_inc_changefeed_count")("{#{client_name}:#{cnt[client_name]} ...}")
        ids[changefeed_id] = client_name

    # Corresonding decrement of count of the number of changefeeds by a given client.
    _dec_changefeed_count: (id) =>
        client_name = @_user_get_changefeed_id_to_user[id]
        if client_name?
            @_user_get_changefeed_counts?[client_name] -= 1
            delete @_user_get_changefeed_id_to_user[id]
            cnt = @_user_get_changefeed_counts
            @_dbg("_dec_changefeed_count")("counts={#{client_name}:#{cnt[client_name]} ...}")

    # Handle user_query when opts.query is an array.  opts below are as for user_query.
    _user_query_array: (opts) =>

        if not user_query[primary_key]? and user_query[primary_key] != null
            cb("changefeed MUST include primary key (='#{primary_key}') in query")
            return
        watch  = []
        select = {}
        init_tracker = tracker = undefined
