New database compression assists in the IBM z14 processor

In this paper, we describe how the IBM z14 processor, together with Db2 for z/OS Version 12, can improve data compression rates and thus reduce data storage requirements and cost for large databases. The new processor improves on the compression hardware accelerator available in earlier IBM Z generations by adding new hardware algorithms that increase the compression ratio and extend the applicability to additional data structures in Db2 for z/OS databases. A new entropy coding step employed after Ziv–Lempel compression reduces the size of data compressed with the prior algorithms by 30% on average. Moreover, the new order-preserving compression algorithm enables database index compression, reducing index sizes by roughly 30%. This results in an overall improvement of 30% of the database size for many applications, with associated benefits in storage requirements, input/output bandwidth, and buffer pool efficiency.