Image copy decompression requires hardware support for the ESA/390 hardware instruction CMPSC. Verify that your hardware supports this instruction. If you enabled PowerExchange zIIP exploitation, decompression uses zIIP processing if available.

If you use zIIP processing, PowerExchange can dispatch an array of compressed rows to the zIIP processor for expansion. The

Array Size

connection attribute controls the number of rows that are dispatched.

Informatica recommends that you use the default array size of 25 unless you are able to test and determine whether the extra memory that is allocated to a larger array size has been beneficial and has not degraded server performance. If you are able to make these determinations, Informatica recommends an array size of 500 to 1000 if you use a compressed image copy as a data source for PowerExchange bulk data movement and you have enabled zIIP processing on z/OS.

PowerExchange does not support compressed image copies that are created by a COPY TABLESPACE statement that includes the SYSTEMPAGES NO option. If you use an image copy of this type as a data source, PowerExchange issues the following message:

In certain cases, an S0C7 abend might occur.

PowerExchange supports Db2 Huffman compression for compressed image-copy sources for bulk data movement. Huffman compression helps reduce disk space and I/O costs. IBM introduced Huffman compression hardware support on z14 mainframes for compressed table spaces in Db2 Version 12 at function level 504. PowerExchange includes support for Huffman-compressed image-copies through hardware and software on pre-z14 systems.