Patent ID: 6230206
Filing Date: 2001-05-08
Classification: G06F

Abstract:
In a parallel database system having a plurality of database processing nodes for processing database data in parallel, said database processing nodes being interconnected by a communication system having communication paths, each said communication path having communication buffers for transferring database data between database processing nodes along said each communication path and each said database processing node having temporary table storage for storing transient database data for said each database processing node, a method of avoiding deadlock in said parallel database system, comprising the steps of:sending database data along a plurality of said communication paths, each said communication path connecting a first database processing node to a second database processing node using the communication buffers of said each communication path;if a communication path of said plurality of communication paths becomes blocked for a predetermined period of time, using the temporary table storage of one of the first or second database processing nodes of said blocked communication path to form a temporary overflow buffer and transferring blocked data from said blocked communication path to the temporary overflow buffer until the blocked communication path becomes unblocked; and thenafter the blocked communication path becomes once again unblocked, returning the transferred data from the temporary overflow buffer back to the once again unblocked communication path wherein the temporary table storage being used as temporary overflow buffer is a resource of a parallel database application program being executed on the parallel database system.