Specifying sequential buffering for an online system
Use the SBONLINE control statement in the DFSVSMxx member to request sequential buffering for an IMS or IBM® CICS® Transaction Server for z/OS® system.
This statement applies to the IMS DB/DC or DBCTL environments. SBONLINE requests loading of SB modules and specifies the maximum amount of buffer space that SB can use.
The format of the SBONLINE control statement is as follows:
Control statements for specifying sequential buffering for an online system
Parameter descriptions for specifying sequential buffering for an online system
- SBONLINE =
- Specifies that sequential buffering modules are to be loaded in the IMS DB/DC or DBCTL environments, thereby allowing subsequent use of
sequential buffering.
By default, IMS does not load the SB modules. This prevents an increase in virtual storage requirements.
- MAXSB=nnnn
- Specifies the maximum amount of space (in kilobytes) that can be allocated to
SB buffers. This number represents the total amount of space to be allocated for all
concurrently executing programs, not for just one individual program. Setting a limit on the amount
of SB space protects you from allocating excessive virtual storage. The default for MAXSB is
unlimited space.
When the MAXSB limit is reached, IMS stops allocating SB buffers until terminating programs release buffer storage.