Reporting Efficiencies

This chapter explains how the Interface optimizes report generation. It includes the following topics:

Interface optimization (see Interface Optimization).

How the Interface constructs DL/I calls (see DL/I Calls).

Record selection tests (see Record Selection Tests).

Joins (see The Dynamic JOIN Command).

Retrieval of unique segments (see Retrieval of Unique Segments).

JOINs with selection criteria (see JOINs With Selection Criteria).

Topics:

Interface Optimization

DL/I Calls

Record Selection Tests

The Dynamic JOIN Command

Retrieval of Unique Segments

JOINs With Selection Criteria

Note:

See the FOCUS for IBM Mainframe Users Manual for information about retrieval of parent segments that lack descendant instances (short paths) and retrieval of segments from multiple paths in the hierarchy (multi-path requests).

When you issue a request in a shared database environment, if an IMS call returns a GG status code (indicating an enqueue), the Interface attempts to retrieve the segment again. The request does not fail unless the Interface detects the GG status code ten times in succession.

If the call still fails after 10 attempts, the user receives a message indicating that the report is incomplete, and the report is displayed with all records retrieved up until that time.

This chapter includes sample report requests. Refer to Sample File Descriptions, for complete file descriptions of the databases referenced in these examples.

Information Builders