Give a better error message when trying to change

"effective_io_concurrency" on systems without posix_fadvise().

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index ecb9505aea7e5c1afa0dfc5a2de347901eaa1a75..47cb894e8edfb92649e14f9e25d9578f660cadad 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.498 2009/04/02 03:51:43 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.499 2009/04/02 19:57:19 momjian Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -1713,7 +1713,13 @@ static struct config_int ConfigureNamesInt[] =
        },
 
        {
-               {"effective_io_concurrency", PGC_USERSET, RESOURCES,
+               {"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.")
                },