Allocating Nonstandard External Files

To allocate a new ISAM file, you must use either a JCL DD statement or the TSO ALLOCATE command; you cannot use the FILENAME statement or FILENAME function. However, you can use the FILENAME statement or function to allocate an existing ISAM file.

For more information, see Accessing UNIX System Services Files.

To allocate a partitioned data set extended (PDSE), specify the appropriate options in the FILENAME statement or FILENAME function, as shown in the example in FILENAME Statement Examples.

For definitions of SMS options, see Options That Specify SMS Keywords.

You can use a PDSE wherever you can use a PDS, and you can write to multiple members in a PDSE at the same time.