EXPORTING › EXPORT Optional Parameters › MERGIN › How an Export with MERGIN Works on Single Catalogs

How an Export with MERGIN Works on Single Catalogs

The following process explains how an export with MERGIN works on single catalogs.

1. CA FAVER opens a file, ddname, and reads the first record.
2. CA FAVER finds and opens the first catalog where the first cluster was exported.
3. CA FAVER reads the first catalog cluster.
4. CA FAVER compares the timestamps (which tell the date and time of the last update) of the cluster name from MERGIN with the cluster name from the catalog:
   • If the timestamp is equal to the cluster and DROP is specified, the MERGIN cluster is not copied to FVROUT because the backup on the MERGIN file is still current.
   • If the timestamp is equal to the cluster and DROP is not specified (the default), the cluster is copied from MERGIN to FVROUT.
   • If the timestamp is greater than the cluster, the cluster on disk is updated after the MERGIN export. The updated cluster is exported to FVROUT.
   • If the timestamp is less than the cluster, the catalog has been back-leveled, possibly because of a volume restore. The error message GV304 is displayed and CA FAVER terminates.
5. CA FAVER compares the catalog and cluster names. If the cluster name from MERGIN is less than the cluster name from the catalog, then the MERGIN cluster from MERGIN is deleted from the catalog after the export.
   • If CARRY is specified, the deleted MERGIN cluster is copied to FVROUT.
   • If CARRY is not specified, the MERGIN cluster is not copied to FVROUT. This is the default.
6. CA FAVER compares the catalog and cluster names. If the cluster name from MERGIN is greater than the cluster name from the catalog, then the cluster from the catalog is defined after the export. The new cluster is exported to FVROUT.

End-of-File Considerations:

• If both the catalog and MERGIN reach end-of-file at the same time (the same number of clusters are in each), CA FAVER continues to the next EXPORT group or end-of-job.
• If MERGIN reaches end-of-file before the catalog, then the remaining clusters in the catalog are created after the MERGIN export. These new clusters are exported to FVROUT.
• If the catalog reaches end-of-file before MERGIN, the clusters remaining on MERGIN are deleted from the catalog and processed according to the CARRY.