gtpd1m1hDatabase Reference

Database Reorganization Control Records

This section describes the control records used with DBR. These control records are defined in the DB0DB data macro.

Master Keypoint

The master keypoint contains information necessary to control the capture of the fixed file and pool database. It contains information relating to each fixed file record type and pool record type available in the system. The master keypoint is a 4KB record that contains bits for all possible record types in the system. These bits indicate:

In addition, the master keypoint contains the available ECB count. The default ECB count is 4; however, you can modify this.

Working Keypoint

The working keypoint is used to control the processing of DBR during output and input phases. When you enter a START command, the master keypoint is copied to the working keypoint to prevent the loss of the master keypoint if a system error or restart occurs. The DBR code periodically saves the last record type processed in the DBR working keypoint so that you can use the RESTART function to restart DBR at that record type.

Override Keypoint

The override keypoint is used to process a START rectype END command. This allows you to capture selected record types or groups of records in a record type without disturbing the master keypoint. Each record type that you enter turns on a bit in a 4KB record associated with the override keypoint to show that record type is to be captured. Once the END parameter is found, the override keypoint is copied to the working keypoint and the DBR output phase is started to capture the selected record types.

Database Reorganization Exception Records

The exception records control which records in individual record types will be bypassed during the DBR output phase. Each ordinal number range of a bypass command for a record type is placed in this record. The exception record can contain up to 256 different sets of ordinal numbers. When the output phase is running, each record type is checked to see if exceptions exist. If exceptions exist, each ordinal number is compared to the exception entries to see if it should be bypassed.