Changes to BLU Acceleration features in Db2 11.5.7

To support new and changed functionality in Db2 11.5.7, changes have been made to Db2 support for column-organized database tables (BLU Acceleration).

Attention: This mod pack release is currently available for the following Db2 products:

Db2 on-premises
The single container deployments of Db2 Warehouse and IBM Integrated Analytics System (IIAS).
The container micro-service deployment of Db2 on Red Hat OpenShift.

Db2 as a Service and Db2 Warehouse SaaS will be updated to version 11.5.7 early in 2022.

BLU Acceleration feature changes

Table 1. Changes to features of column-organized tables in Db2 11.5.7
Feature	New behavior
Real-time statistics feature now performs synchronous statistics collection for column-organized tables	With the release of Db2 11.5.7, synchronous statistics collection now occurs when the query optimizer collects statistics for column-organized tables. As a result, an increase of up to 5 seconds for SQL prepare time could occur for queries that reference column-organized tables. This behavior can be disabled by setting DB2_REDUCED_OPTIMIZATION="COL_RTS OFF"