The Standard Search Order

Most catalog searches should be based on catalog aliases. When appropriate aliases are defined for catalogs, the high-level qualifier of a data set name is identical to a catalog alias and identifies the appropriate catalog to be used to satisfy the request. However, some alternatives to catalog aliases are available for directing a catalog request, specifically the CATALOG parameter of access method services and the name of the catalog.

Table 1 summarizes the catalog search order for defining or locating a data set.

Table 1. Standard Search Order for Catalog Requests
Defining a Data Set	Locating a Data Set
Use the catalog named in the IDCAMS CATALOG parameter, if coded. If the data set is a generation data set, the catalog containing the GDG base definition is used for the new GDS entry. If the high-level qualifier is a catalog alias, use the catalog identified by the alias or the catalog whose name is the same as the high-level qualifier of the data set. If no catalog has been identified yet, use the master catalog.	Use the catalog named in IDCAMS CATALOG parameter, if coded. If the data set is not found, fail the job. If the data set is a generation data set, the catalog containing the GDG base definition is used for the new GDS entry. If not found, and the high-level qualifier is an alias for a catalog, search the catalog or if the high-level qualifier is the name of a catalog, search the catalog. If the data set is not found, fail the job. Otherwise, search the master catalog.
Restriction: For DEFINE USERCATALOG, the catalog will be added to the master catalog of the running system whether the CATALOG parameter is used or not.

To use an alias to identify the catalog to be searched, the data set or object name, or the generation data group base name, must be a qualified name.

The catalog search order is modified when the CATALOG parameter of access method services commands is used to direct the catalog request. When you specify a catalog in the CATALOG parameter, and you have appropriate RACF® authority to the FACILITY class profile STGADMIN.IGG.DIRCAT, the catalog you specify is used.

For instance, DEFINE USERCATALOG CATALOG(SYS1.MASTER.ICFCAT) defines a catalog with a connector record in SYS1.MASTER.ICFCAT, even if SYS1.MASTER.ICFCAT is not the master catalog on the system where you issue the command. See Storage Administration (STGADMIN) Profiles in the FACILITY Class for more information on the RACF directed catalog profile.