Remove postmaster.c's check that NBuffers is at least twice MaxBackends.

With the addition of multiple autovacuum workers, our choices were to delete
the check, document the interaction with autovacuum_max_workers, or complicate
the check to try to hide that interaction.  Since this restriction has never
been adequate to ensure backends can't run out of pinnable buffers, it doesn't
really have enough excuse to live to justify the second or third choices.
Per discussion of a complaint from Andreas Kling (see also bug #3888).

This commit also removes several documentation references to this restriction,
but I'm not sure I got them all.

1 files changed, 1 insertions, 11 deletions

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 2c481f93bbf..7a83e075b18 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.552 2008/02/20 22:46:24 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.553 2008/03/09 04:56:28 tgl Exp $
  *
  * NOTES
  *
@@ -688,16 +688,6 @@ PostmasterMain(int argc, char *argv[])
 	/*
 	 * Check for invalid combinations of GUC settings.
 	 */
-	if (NBuffers < 2 * MaxBackends || NBuffers < 16)
-	{
-		/*
-		 * Do not accept -B so small that backends are likely to starve for
-		 * lack of buffers.  The specific choices here are somewhat arbitrary.
-		 */
-		write_stderr("%s: the number of buffers (-B) must be at least twice the number of allowed connections (-N) and at least 16\n", progname);
-		ExitPostmaster(1);
-	}
-
 	if (ReservedBackends >= MaxBackends)
 	{
 		write_stderr("%s: superuser_reserved_connections must be less than max_connections\n", progname);