Bruce Momjian wrote:
> Tom Lane wrote:
> > Peter Eisentraut <peter_e@gmx.net> writes:
> > > Joshua D. Drake wrote:
> > > Do we want to give a more informative error message, like "not supported
> > > on this platform?"
> >
> > > The trick will be to fit this into the GUC framework.
> >
> > You could do it by enforcing the limit in an assign hook, but I'm
> > not convinced it's worth the trouble.
>
> I have created a patch to at least display a more helpful message,
> without being specific:
>
> test=> set effective_io_concurrency = 1;
> ERROR: parameter "effective_io_concurrency" cannot be changed from 0
I fixed this an easier way, by making the parameter PGC_INTERNAL on
systems that don't have posix_fadvise().
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
Index: src/backend/utils/misc/guc.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/misc/guc.c,v
retrieving revision 1.497
diff -c -c -r1.497 guc.c
*** src/backend/utils/misc/guc.c 9 Mar 2009 14:34:34 -0000 1.497
--- src/backend/utils/misc/guc.c 2 Apr 2009 19:52:49 -0000
***************
*** 1713,1719 ****
},
{
! {"effective_io_concurrency", PGC_USERSET, RESOURCES,
gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
},
--- 1713,1725 ----
},
{
! {"effective_io_concurrency",
! #ifdef USE_PREFETCH
! PGC_USERSET,
! #else
! PGC_INTERNAL,
! #endif
! RESOURCES,
gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
},