Support of PROCOPT=R and replace calls
PROCOPT=R is supported for compatibility. If a database is shared at the database level when PROCOPT=GR, DBRC grants access with integrity for updating the IMS subsystem.
Status code in PCB feedback
The following DL/I status codes, in addition to the blank status code, are returned after a REPL call for an HSSR PCB:
- Status code
- Unable to find the segment.
- There is a duplicate segment in the unique secondary index.
- VX is used during a REPL call to signal that the application program has not respected the restrictions for HSSR Engine. When VX is displayed, the replace was not performed. Database positioning information is maintained normally.
HSSR Engine handles replace calls by issuing IMS DL/I GH and REPL calls internally. IMS uses its own OSAM or VSAM buffer pools to process these DL/I calls.
If your application program issues REPL calls, the usual DFSVSAMP control statements must be coded to tune the processing of these internal DL/I calls.
The following restrictions apply to PROCOPT=R and replace calls:
- PROCOPT=R cannot be specified for HISAM, SHISAM, or secondary index databases.
- PROCOPT=R cannot be specified for PHDAM or PHIDAM databases.
- PROCOPT=R cannot be specified for logical child segments that
have the following attributes:
- Physically paired
- Logical parent's concatenated key defined as VIRTUAL if the BLDLPCK control statement is not specified in the HSSROPT data set
- PROCOPT=R cannot be specified for secondary index source segments other than root segments.
- The REPL call for PHDAM and PHIDAM databases is not supported.
- The segment length of a variable or compressed segment must not be modified by a replace call.
Support and restriction for replace operations
HSSR Engine provides limited support of replace calls for application programs that replace a small or moderate number of retrieved database segments and modify a small or moderate number of accessed database blocks or CIs. This support includes standard IMS logging of database changes, standard IMS sync point processing, and a standard DBRC interface as provided by the host IMS batch subsystem.