PDSE enhancements for z/OS V2R1

z/OS® V2R1 adds the following PDSE enhancements:

• Increased PDSE member size limits. The maximum PDSE member size increases from 15 728 639 records to 2 146 435 071 records. The larger size limit applies to PDSEs being accessed with various sets of characteristics, including DSORG and MACRF values, whether they are open for input or output, and whether BLOCKTOKENSIZE=LARGE is specified. For a list of the PDSE access characteristics that support the larger member size limit, see the topic on "PDSE member size limits" in z/OS DFSMS Using Data Sets.
• New PDSE version. z/OS V2R1 introduces a new version of PDSE data sets that can provide for improved performance, reduced path lengths, and improved index searches. New data sets can be allocated as belonging to the new version (version 2) by specifying a new positional parameter in the DSNTYPE keyword of the DD statement or TSO/E ALLOCATE command, or by specifying a new PARMLIB option (PDSE_VERSION) in IGDSMSnn members. Unless version 2 is specified, new allocations continue to create the current version 1 PDSE data sets. Externally, version 1 and version 2 PDSEs look the same, and both versions can be open for input/output with no changes for the users. For more information about the new PDSE version and how to specify it, see the topic "PDSE Version" in z/OS DFSMS Using Data Sets.