Typical benefits of PSSR

Physical Sequence Sort for Reload sorts an unloaded database data set that is produced for an HDAM database to reduce the elapsed time that is required to reload the database. It also generates reports that help you conduct performance and tuning analysis.

The PSSR utility offers the following benefits:

Reduces elapsed time to reload a database

  • Converting database organization to HDAM-type
    • Non-HDAM to HDAM
    • Non-PHDAM to PHDAM
  • Converting database organization to HIDAM-type
    • Non-HIDAM to HIDAM
    • Non-PHIDAM to PHIDAM
  • Converting database organization to HISAM-type
    • Non-HISAM to HISAM
    • Non-SHISAM to SHISAM
  • Changing HDAM randomization parameters (HDAM/PHDAM)
  • Changing partition selection exit or High key of HALDB
  • Adding or deleting partitions of HALDB

Helps prevent cascading

PSSR helps to avoid the cascading of root segments during reorganization. It does so by loading some database records at the end of the reload, instead of loading them in their normal physical sequence.
Important: If you reload a database by using IMS High Performance Load 2.1, you cannot use PSSR to prevent cascading. To prevent cascading and avoid degradation of performance in reloading, it is recommended that you use the SORT=YES and the SEARCH=-nnn parameter instead of using PSSR.

Helps conduct performance and tuning analysis

PSSR helps you conduct performance and tuning analysis by generating the following reports:
  • Reports about database record sizes
  • Reports about DBD parameters
  • Reports about randomization