Private buffer pools

IMS provides special private buffer pools for Shared VSO areas. Each pool can be associated with an area, a DBD, or a specific group of areas.

These private buffer pools are only used for Shared VSO data. Using these private buffer pools, you can request buffer lookaside for the data. To specify whether buffer lookaside is used on read requests, use one of the following methods:
  • The LKASID or NOLKASID keyword on the INIT.DBDS or CHANGE.DBDS DBRC command
  • The LKASID or NOLKASID value on the DFSVSMxx member of the IMS PROCLIB data
If both of the methods in the preceding list are used, the value specified by using the DBRC command takes precedence over the value specified by using the DFSVSMxx PROCLIB member.

For VSO DEDB areas that use a single-area structure, you must specify whether buffer lookaside is used. The value that is defined in the RECON data set for the area by using one of the DBRC commands takes precedence over the value defined in the DFSVSMxx PROCLIB member.

For VSO DEDB areas that use a multi-area structure, LKASID or NOLKASID must be specified by using the DFSVSMxx PROCLIB member. Specifications in the RECON data set are ignored.