BUG #7858: Inaccurate Log Message

The following bug has been logged on the website:

Bug reference: 7858
Logged by: Jackie Zhang
Email address: jackie(dot)qq(dot)zhang(at)gmail(dot)com
PostgreSQL version: 9.1.4
Operating system: Ubuntu
Description:

Hi,

The log message of the sanity check for "superuser_reserved_connections" in
PostmasterMain() is not accurate. See the following code snippet:

/*src/backend/postmaster/postmaster.c*/
730 /*
731 * Check for invalid combinations of GUC settings.
732 */
733 if (ReservedBackends >= MaxBackends)
734 {
735 write_stderr("%s: superuser_reserved_connections must
be less than max_connections\n", progname);
736 ExitPostmaster(1);
737 }

The problem is that "MaxBackends" is calculated by both
"autovacuum_max_workers" and "max_connections". See assign_maxconnections()
and assign_autovacuum_max_workers() in src/backend/utils/misc/guc.c.

The log message should inform both the two configuration parameters instead
of only one -- the root cause could be the oversized
"autovacuum_max_workers".

Thanks,
Jackie