You can optionally include a Lookup transformation in a mapping for a bulk data movement to add related values from a lookup source or to determine if some of the records already exist on the target.

In a Lookup transformation, you must indicate the key fields that you want PowerExchange to use in the Segment Search Argument (SSA) for searching the IMS database. Concatenated keys (CCK) fields achieve the best performance and have the least impact on the IMS database.

To minimize contention on the IMS database during lookup processing, also create the IMS PCBs with the PROCOPT=GO

x

parameter. This parameter indicates what IMS should do if it encounters an invalid pointer while reading a segment that is being updated.

For more information about Lookup transformations, see

PowerExchange Interfaces for PowerCenter

and

PowerCenter Transformation Guide

.