Restrictions on Defining Extended-Format Data Sets

The following restrictions apply to defining extended-format data sets:

An extended-format data set does not permit the indexes to be imbedded with the data (IMBED parameter) or the data to be split into key ranges (KEYRANGES parameter).
Extended-format data sets must be SMS managed. These are the mechanisms for requesting extended format for VSAM data sets:
- Using a data class that has a DSNTYPE value of EXT and the subparameter R or P to indicate required or preferred.
- Coding DSNTYPE=EXTREQ (extended format is required) or DSNTYPE=EXTPREF (extended format is preferred) on the DD statement.
- Coding the LIKE= parameter on the DD statement to refer to an existing extended format data set.
Note: The maximum number of paging slots for each page space is 16M. Page spaces regardless of their size have the extended format and extended addressable attributes assigned to them whether they are on an SMS managed volume or a non-SMS managed volume.
An open for improved control interval (ICI) processing is not permitted for extended format data sets.