Performance enhancements

Db2 11.5.2 contains numerous SQL performance enhancements that continue to make the Db2 data server an industrial-strength data server solution that is suitable for any size of organization.

Attention: The enhancements in this topic are included in the Db2 11.5.2 mod pack release, which is available only for single container deployments of Db2 Warehouse and IBM Integrated Analytics System (IIAS).
The following table lists performance enhancements that have been added to the container-only release of Db2 11.5.2:
Table 1. Performance enhancements in 11.5.2
Enhancement Description
Improved performance of Hash Joins (HSJN) that have a single equality join predicate and one, or more, non-equality joins predicates when accessing columnar tables This improvement enables Hash Joins joining columnar tables or streams to apply additional non-equality join predicates during the main Hash Join for optimized performance.
Early aggregation / early distinct for column-organized queries

Additional strategies have been introduced for column-organized query planning. These strategies will help improve query performance by aggregating and removing duplicates earlier as the query is run.

These strategies are counterparts to existing strategies used in row-organized query planning.