About this information

This document identifies key performance benefits and tuning considerations when using IBM® Enterprise COBOL for z/OS® Start of changeVersion 6 Release 2End of change.

First, this document gives an overview of the major performance features and options in Version 6 of the compiler, followed by performance improvements for several specific COBOL statements. Next, it provides tuning considerations for many compiler and runtime options that affect the performance of a COBOL application. Coding techniques to get the best performance are examined next with a special focus on any coding recommendations that have changed when using Version 6.

The final section examines some causes of increased program object size and studies the object size impact of the various new TEST suboptions as well as discussing the related issue of why PDSEs are required for programs compiled using Version 6.

The performance characteristics of Version 5 of the compiler are similar to Version 6. Except where otherwise noted, the information and recommendations in this document are also applicable to Version 5. Because the performance tuning changes required during migration from Version 5 to Version 6 are so small, recommendations and comparisons in this document assume that the reader is migrating from Version 4 of the compiler.