Patent ID: 7797333

Claim:
A database system for processing a query request, comprising: a first master node running on at least one first processor for: communicating a request to perform one or more activities associated with a precompiled query over at least one communication channel of the database system, receiving a request-to-send message from a first slave node on a flow control communication channel, wherein the flow control communication channel is accessible by a plurality of master nodes including the first master node and another master node, listening, after receiving the request-to-send message, to the flow control communication channel for messages between the first slave node and the another master node to determine an availability of the first slave node at least based on whether or not the first slave node is currently sending results to the another master node, communicating a permission-to-send message to the first slave node, if it is determined from the listening on the flow control communication channel that the first slave node is available because it is not currently sending results to the another master node, wherein the permission-to-send message is valid for a predefined period of time, and communicating the permission-to-send message to a second slave node if it is determined from the listening on the flow control communication channel that the first slave node is unavailable because it is currently sending results to the another master node; and a plurality of slave nodes running on at least one second processor coupled to the first master node, at least a particular one of the slave nodes for: receiving over the communication channel the request communicated by the first master node; performing at least a portion of the one or more activities associated with the request to obtain one or more results for the request; communicating the request-to-send message to the first master node indicating that the one or more results are available for communication to the first master node; and communicating at least a portion of the one or more results to the first master node in response to receiving the permission-to-send message from the first master node.