At 11:57 -0600 on 01/21/2013, Paul Gilmartin wrote about TSO ALLOCATE
REUSE ENQ?:
How can restriction be? It seems that if the file is first FREEd, the ENQ is
removed and reallocating SHR should just work. What's going on here
that they're not telling me.
They are hiding the MAJOR design-flaw/Bug in ENQ which does not
support the conversion of an EXC ENQ into a SHR ENQ. All that should
be needed is to alter the EXC to SHR in the table and then use the
code that is run by DEQ to run the waiting queue resuming tasks until
it is empty or an EXC is found. There is support to alter a SHR to
EXC (ENQ TYPE=CHG) but that code is not always going to work since
you must be the ONLY SHR owner so you can switch to EXC.
Why they have never fixed this design flaw is a crime since there are
a number of cases where it would help such as the unneeded DISP=OLD
holds that could be converted to DISP=SHR once the step that needs
for the DISP=OLD ends (since all subsequent steps only say DISP=SHR)
and thus make the system more responsive.
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN
