Data set names of the IMS directory data sets

By default, the high-level qualifier (HLQ) of the IMS directory data sets are derived from the data set name prefix of the IMS catalog database data sets.

IMS defines the characters of the final qualifier for these data sets as follows:

IMS directory data sets: DI followed by a suffix that IMS creates automatically
IMS bootstrap data set: BSDS
Staging data set: STG

The data set name prefix of the IMS catalog database data sets from which the default HLQ of the directory data sets is derived, is defined in the RECON data set when the first partition is defined to DBRC or the IMS Catalog Definition exit routine (DFS3CDX0). If the IMS catalog is not registered with DBRC, the data set name prefix of the IMS catalog database data sets is defined in the partition definition data set (PDDS).

The following example shows the default names for the IMS directory data sets if you were to specify DSNPREFX(IMSTEST.DFSCD000) on the INIT.PART command for the first partition of the IMS catalog database:

IMSTEST.DFSCD000.DI1001
IMSTEST.DFSCD000.DI1002
IMSTEST.DFSCD000.BSDS
IMSTEST.DFSCD000.STG

To use a different data set name prefix for the IMS directory and its associated data sets, you can specify a high-level qualifier (HLQ) for them on the SYSDSHLQ= parameter in a dynamic allocation macro (DFSMDA) before you run the IMS Catalog Populate utility (DFS3PU00) to create them.

You can specify the SYSDSHLQ= parameter in a TYPE=CATDSHLQ statement in the DFSMDA macro.

After the IMS directory data sets are created, what you specify to access the directory data sets and where you specify it depends on how the HLQ was defined and what you need to do.

For example, if the HLQ for the IMS directory was defined by using the CATDSHLQ DFSMDA macro statement, when you run the IMS Catalog Library Builder utility (DFS3LU00), you can specify on the IMSCATHLQ= control statement either the HLQ of the directory data sets or the value of the DDNAME parameter in the CATDSHLQ DFSMDA macro. If both are specified, the utility checks for the DFSMDA member first.

Similarly, if you issue the OPEN call of the IMS Catalog API when the HLQ is defined by the CATDSHLQ DFSMDA macro, you can access the IMS directory by specifying the alias name of the IMS catalog on the CATALIAS= parameter.