Patent ID: 9141609
Filing Date: 2015-09-22
Classification: G06F

Abstract:
1. A computer implemented method for reducing sequence cache latch access contention in a database system having a plurality of concurrently executing session processes on a database instance, the method comprising: establishing a master list comprising a plurality of sequence objects, the sequence object to define a sequence of values; providing a first latch to serialize access to the master list such that at any point in time, only one of the concurrently executing session processes is granted access to the master list; allocating a sequence from the master list to the database instance, the allocated sequence being stored in a cache storage location accessible to the concurrently executing session processes on the database instance; providing a plurality of child latches corresponding to a plurality of segments of the allocated sequence, wherein the plurality of child latches are used to serialize access to the corresponding plurality of segments, such that at any point in time, only one of the concurrently executing session processes is granted access to a particular segment of the plurality of segments; and wherein a number of the plurality of child latches is determined by using at least a cache size and a number of processing entities available to the concurrently executing session processes.