Benefits of sequential buffering

By using OSAM sequential buffering (SB), any application program or utility that sequentially processes OSAM data sets can run faster.

Because many other factors affect the elapsed time of a job, the time savings is difficult to predict. You need to experiment with SB to determine actual time savings.

Programs that can benefit from SB

Some of the programs, utilities, and functions that might benefit from the use of SB are:

  • IMS batch programs that sequentially process your databases.
  • BMPs that sequentially process your databases.
  • Any long-running MPP, Fast Path, and CICS® programs that sequentially process your databases.
    Note: SB is possible but not recommended for short-running MPP, IFP, and CICS programs. SB is not recommended for the short-running programs, because SB has a high initialization overhead each time such online programs are run.
  • IMS utilities, including:
    • Online Database Image Copy
    • HD Reorganization Unload
    • Partial Database Reorganization
    • Surveyor
    • Database Scan
    • Database Prefix Update
    • Batch Backout
  • HALDB Online Reorganization function

Typical productivity benefits of SB

By using SB for programs and utilities that sequentially process your databases, you might be able to:

  • Run existing sequential application programs within decreasing batch window times. For example, if the time you set aside to run batch application programs is reduced by one hour, you might still be able to run all the programs you normally run within this reduced time period.
  • Run additional sequential application programs within the same time period.
  • Run some sequential application programs more often.
  • Make online image copies much faster.
  • Reduce the time needed to reorganize your databases.