Cluster based Mixed Coding Schemes for Inverted File Index Compression

One way to improve inverted file compression is to use the cluster property [1] of document collection, which states that term occurrences are not uniformly distributed. Some terms are more frequently used in some parts of the collection than in others. The corresponding part of the inverted list will consequently be small d-gap values clustered. Interpolative code [9] exploits the cluster property of term occurrences and achieves very good performance. Other codes that favor small d-gaps also perform well on document collections with cluster property.