EXTRACT (Extract Data Table) › When to Use › Extracting in Physical Key Sequence

Extracting in Physical Key Sequence

With UPDATE=YES, the physical extract occurs with the rules as previously described (for Native Key sequence).

Without UPDATE=YES, the physical extract executes with few requirements and no protection. It was designed for the special case of extracting the data with I/O errors or during maintenance for a hot backup. With no protection, the data is the best that it is possible to get by reading what is on the DASD at the time it is read. This option should be executed when the submitter is watching or controlling other activity.

Use the EXTRACT function to verify the integrity of every data block in a data area. To activate this feature, code 'DUMMY' for the DDNAME= keyword value (DDNAME=DUMMY) and also code 'DUMMY' on the JCL DD statement.

 //DUMMY DD DUMMY

If any block in the data area is determined to be invalid, the DBUTLTY execution terminates with a S000 U004 abend. Additionally, it produces one DB13155W message for each invalid data block found. SNAP dumps are produced for the first ten errors encountered.