Patent ID: 9262434
Filing Date: 2016-02-16
CPC Classification: G06F,H03M

Claim Text:
1. A computer-implemented method for improving efficiency in a delta compression process in a data storage system, the method comprising: selecting a data chunk to delta compress; generating a sketch for the selected data chunk; searching for a set of candidate data chunks using the sketch; ranking the set of candidate data chunks by degree of sketch matching; tie-breaking the set of candidate data chunks, where the set of candidate data chunks has an equal degree of sketch matching, including ranking a candidate data chunk stored in a cache higher than a candidate data chunk stored on a storage device, and, ranking a decompressed candidate data chunk higher than a compressed candidate data chunk having a same location status as the decompressed candidate data chunk; delta compressing the selected data chunk with a selected candidate data chunk of the ranked set of candidate data chunks; and storing the delta compressed selected data chunk in the data storage system.