ILE COBOL Programmer's Guide

Database Features that Support Referential or Check Constraints

The following database features support referential and check constraints:

Journaling

A file with referential or check constraints can be journaled, but it is not required to be. There are not any special journal entries associated with check constraints.

Commitment Control

When commitment control is active, file I/O functions follow the same rules that apply when commitment control is not active. That is, when performing I/O on a file with constraints, an insert, update, or delete is not allowed where a constraint rule would be violated. Potential violations result in notification messages. If the I/O operation completes successfully, then either a COMMIT or ROLLBACK can be performed.

Distributed Data Management (DDM)

Check constraints are supported for Distributed Data Management (DDM) files. When DDM is being used between a V4R2 and a pre-V4R2 system, then any check constraint information that may exist on the V4R2 system is not passed to the pre-V4R2 system.

When an attempt is made to propagate check constraints between a V4R2 and a pre-V4R2 system for DDM files, the following operations will either not propagate the check constraints or will fail:

Distributed Files

Check constraints are supported for Distributed (multi-system) files. When distributed files are being used between a V4R2 and a pre-V4R2 system, then any check constraint information that may exist on the V4R2 system is not passed to the pre-V4R2 system.

When an attempt is made to propagate check constraints between a V4R2 and a pre-V4R2 system for distributed files, the following operations will fail:


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