Activating sequential buffering to improve the performance of HALDB Online Reorganization

You can use sequential buffering to improve the performance of online reorganization of OSAM databases by including the SBONLINE statement in the IMS.PROCLIB data set member DFSVSMxx.

Using the SBONLINE statement causes IMS to load the sequential buffering modules during initialization so that, whenever you start an online reorganization for an OSAM partition, IMS activates sequential buffering immediately. If you do not include the SBONLINE statement, IMS analyzes the DL/I calls to determine whether sequential buffering is suited for processing the reorganization.

The two forms of the SBONLINE control statement are:

SBONLINE

SBONLINE,MAXSB=nnnnn

where nnnnn is the maximum amount of storage (in kilobytes) that can be allocated to sequential buffers.

When the maximum amount of storage is reached, IMS stops allocating sequential buffers to online applications (including HALDB Online Reorganization) until these applications release sequential buffer space. If you do not specify the MAXSB= keyword, the maximum amount of storage for sequential buffers is unlimited.