DEDB full condition

The database-full condition in a DEDB area indicates that one or more portions of the root-addressable area of the DEDB can no longer accept ISRT calls.

IMS detects the out-of-space condition for DEDB sequential dependent segments during sync-point processing. Although the application program may receive a warning status code, some ISRT calls, issued from a Fast Path message-driven program or from an MPP region, cause the region to abnormally terminate with a U0844 abend code.

Recommendation:  Track space usage within a DEDB area using one of the following methods:

• The application program can use information given by the position (POS) call
• The master terminal operator can monitor it using the appropriate /DISPLAY DB or QUERY DB command to show the total allocated and the total used CIs in both the root-addressable and the sequential-dependent portions of the area.

If a DEDB area does reach the database-full condition, Fast Path provides two online utilities that may negate the need for using an offline application program to perform a database unload and reload operation to resolve the problem. The two utilities are:

• The Sequential Dependent Delete utility, which deletes the sequential-dependent segments in all or part of the sequential-dependent portion of an area. This makes the space available for further sequential dependent inserts.
• The Direct Reorganization utility, which removes space fragmentation in an area. The utility runs against one DEDB area at a time.

  Recommendation:  Although you can limit the reorganization to the one unit of work that did not allow inserts, you should reorganize more or all of the area. Any independent overflow space that is freed from one unit of work becomes available for use by any other unit of work within that area.