There are two methods CA Disk can use to archive and restore alternate indexes. The first method is always performed and cannot be overridden: the catalog information required to redefine an alternate index is always archived with its base cluster. When the base cluster is restored, the alternate index can be redefined from this information. In this case, an entry is made in the CA Disk FILES for only the base cluster and not its alternate index(es).
The second method of archiving an alternate index is to explicitly name it on an archive command with sysparm VSARCAIX specified with a value of Y, or to run a backup of the base cluster with sysparm VSARCAIX specified with a value of Y. This method causes the alternate index to be physically processed as a data set; as such it will have its own entry in the CA Disk FILES and the data records from the alternate index will be read and archived along with the catalog information. Using this latter method, the cluster index will be referred to in this section as the physical alternate index.
If a disposition of DELETE is specified or assumed on the command, alternate indexes will not be archived. This is to ensure the alternate index will not be deleted before the base cluster is processed, which would remove the association from the base cluster.
The alternate index can always be redefined and built based on the catalog information archived with the base cluster. There are special processing considerations required to restore a physical alternate index, and they are detailed later in this section of the manual. Prior to reading the sections on restoring VSAM clusters and alternate indexes, make sure you understand the difference between restoring a physical alternate index as opposed to rebuilding the alternate index from catalog information saved with the base cluster.
It should be noted that clusters that were archived with a release of CA Disk prior to Release 7.5 will not have the alternate index information with the base cluster. It is therefore necessary to redefine the alternate indexes of these clusters manually after the base cluster is restored by CA Disk.
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