DSG
Use the DSG option for two purposes:
- To limit the validation to one or more database data sets
- To specify the input data set groups to scan asynchronously
PCP normally scans all data sets in the entire database serially. The ASYNC and WORKDDN options allow for asynchronous processing.
For HISAM databases and non-unique secondary indexes, specify the ddname of the primary data set only. The overflow data set is implicitly part of the primary-overflow pair, and PCP scans it serially with the primary data set. If you are using the Hash Checking technique in a multiple-step process, do not use the DSG option to limit the check to one data set of the primary-overflow pair; they must always be checked in the same job step.
If you are using this option to limit the validation, you must be knowledgeable about the IMS database structure. You can find the necessary information in a map of the DBD. If you use this option improperly, the results can be misleading.
Uses | You can set the DSG option only on the CHECK control statement. |
|---|---|
ISPF panel field | None |
PCPSYSIN keyword | DSG(ddname1,ddname2,…ddname10) |
Values | Specify from one to ten ddnames (1-8 characters each) of the database data sets to validate. |
Default | None |
Example | The following example scans a single data set group of a database that has multiple data set groups. Data set HDAMDD1 contains parent segment HDAMS1. Data set HDAMDD2 contains child segments HDAMS2 and HDAMS3. PCP validates both logical and physical pointers of segments contained in the specified data set HDAMDD2. CHECK DBD(HDAMDB) DSG(HDAMDD2) Since HDAMS1 is not included in the scan, PCP ignores the following pointers:
Since it did not validate the PCF and LCF pointers, PCP reports errors that might not exist; it reports some HDAMS2 and HDAMS3 segments as physically orphaned and some HDAMS3 segments as logically orphaned. |