GLYPH<SM590000> For the non-partitioned table: 

– A total elapsed time improvement of 72% where only a 4% improvement comes from the use of a shadow table because the delete phase is not a major component of the load. 

– No major change in CPU time. 

Improvements can also be expected for partial table reload on IDAA v4 PTF-3 compared to IDAA v4 PTF-2, in accordance to how much of the table is reloaded. 

## 10.4 IDAA version 4 PTF-4 

This section describes dynamic statement cache support for accelerated queries that was added in IDAA V4 PTF-4. 

## 10.4.1 Dynamic statement cache support for accelerated queries 

Before this feature was available, Db2 did not support dynamic statement caching for accelerated dynamic queries. When an accelerated dynamic query was run, it went through a full PREPARE in Db2 for z/OS. 

This feature improves PREPARE performance for repeated accelerated dynamic queries; long PREPAREs become short PREPAREs by caching the prepared statements in the statement pools. No user action is required to trigger this feature. 

Controlled tests on PREPAREs of seven accelerated dynamic queries showed over 70% Db2 elapsed time improvement and 80% Db2 CPU improvement. 

Tests on PREPAREs of four un-accelerated dynamic queries show no performance difference with and without this feature, as expected. 

## 10.5 IDAA version 4 PTF-5 

This section describes load improvement and a load and query performance comparison of N3001 (Mako full rack) and N2001 (Striper full rack), in-database transformation, parallel incremental updates, and auto keys for incremental update enabled tables. 

## 10.5.1 Load improvement with PI26783 

APAR PI26783 (HIGH CPU CONSUMPTION FOR IDAA LOAD TABLE PROCESS. IMPROVE IDAA LOAD TO SUPPORT UNKNOWN RECORD LENGTH IN DB2 UNLOAD PHASE) reduces CPU-consuming BSAM process during the DB2 UNLOAD step when IDAA loads data from Db2 to an accelerator. This APAR is addressed for Db2 10 and 11 for z/OS. The improvement is included in Db2 12 base code. 

CPU savings are relative to the number of rows in the table. During controlled testing, loading a 29.5 billion row table with an average record length of 131 bytes showed 25% CPU time savings when loading data from a zEC12 LPAR to a full rack Striper with 12 streams, and 30% CPU time savings to a full rack Mako. 

