On Tue, 21 Apr 2015 11:20:24 -0400, Robert A. Rosenberg wrote: >... due to a IMO major design flaw in the ENQ process >the Initiator can be forced to hold an ENQ for subsequent steps where >it is no longer needed. The case I am talking about is there is no >way to convert an EXC ENQ into a SHR one.
From the z/OS 2.1 announcement: <quote> z/OS V2.1 Global Resource Serialization (GRS) supports synchronously changing an exclusive enqueue to a shared enqueue, in addition to the existing support for changing an enqueue from shared to exclusive. Corresponding support is available in JCL for a new JOB statement keyword to enable you to specify that access to data sets can transition from exclusive to shared after the last step in which they are allocated with a disposition of OLD, NEW, or MOD. Also, support is available for a JES2 initialization statement to specify whether this function should be allowed, and whether it should be used by default if not specified in JCL. This function is intended to permit more parallelism in resource processing by allowing resources to be available for read access before the process that originally requested exclusive use ends in single-system and GRS Star environments. </quote> -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
