Secondary indexes and selective partition processing

You can restrict BMP, JBP, and batch-processing applications programs to a subset of one or more contiguous partitions of a HALDB partitioned secondary index (PSINDEX).

To specify selective partitions for processing, specify the name of the PSINDEX partition in the DFSHALDB statement

You can process the partitions of a PSINDEX selectively regardless of whether your application program processes your PSINDEX as a standalone database or as an alternate processing sequence for a PHDAM or PHIDAM database.

The partitions in a PSINDEX do not correspond to the partitions in the PHDAM or PHIDAM database that the PSINDEX indexes. Consequently, when you specify selective partition processing for a PSINDEX, selective partition processing applies only to the PSINDEX partition, not to the partitions of the PHDAM or PHIDAM database. The target segments can be in any partition in the indexed PHDAM or PHIDAM database.

Similarly, if you specify selective partition processing for a PHDAM or PHIDAM database, the selective partition processing does not restrict access to any of the partitions in any associated PSINDEXs.

Regardless of whether you are using selective partition processing with a PSINDEX or with an indexed PHDAM or PHIDAM database, selective partition processing does not affect the internal updating of a secondary index by IMS when a target segment is updated. For example, if an application program is restricted to a single partition of the PSINDEX and inserts a segment into the indexed PHDAM or PHIDAM database, the corresponding new index entry can be inserted in any partition of the PSINDEX.