Working with Criteria

When you use the Extract dialog (option 3.3) to generate a batch job that extracts segments from IMS databases, you can specify a criteria set to determine:

  • the segments to be extracted.
  • the database records (root and all dependents) to be extracted using field selection criteria.
  • how logical relationships between databases are extracted using Relationship Criteria.

A criteria set contains one relationship criteria subset and up to n subsets containing field selection criteria for determining the database records to be extracted.

Each field selection criteria subset is applied to a database record separately. Duplicate records are removed using a sort utility after the extract is completed.

You can create and edit a criteria set in the Extract dialog, or you can use Criteria (option 4.3) to create and edit a criteria set for later use.

Before you can create a criteria set, you must already have created a template for the associated database.

Within a subset, you can specify criteria for each segment type in the database (for segment types with more than one layout, you can specify criteria for each layout). If a root segment and all of its hierarchical dependents (at every level) match their criteria, then the root segment is extracted, along with all of its dependents. However, if any segment does not match its criteria, then its root segment, and all of the root segment's hierarchical dependents, are not extracted.

A criteria set always contains a relationship criteria subset. If the database contains logical relationships, then you can use this subset to determine if FM/IMS extracts an occurrence of a logical relationship.

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