Convert the arithmetic for shared memory size calculation from 'int'

to 'Size' (that is, size_t), and install overflow detection checks in it.
This allows us to remove the former arbitrary restrictions on NBuffers
etc.  It won't make any difference in a 32-bit machine, but in a 64-bit
machine you could theoretically have terabytes of shared buffers.
(How efficiently we could manage 'em remains to be seen.)  Similarly,
num_temp_buffers, work_mem, and maintenance_work_mem can be set above
2Gb on a 64-bit machine.  Original patch from Koichi Suzuki, additional
work by moi.

1 files changed, 2 insertions, 3 deletions

diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c
index 3768570ad3d..4a2e1f55927 100644
--- a/src/backend/access/transam/clog.c
+++ b/src/backend/access/transam/clog.c
@@ -24,7 +24,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/clog.c,v 1.31 2005/06/30 00:00:50 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/clog.c,v 1.32 2005/08/20 23:26:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -144,8 +144,7 @@ TransactionIdGetStatus(TransactionId xid)
 /*
  * Initialization of shared memory for CLOG
  */
-
-int
+Size
 CLOGShmemSize(void)
 {
 	return SimpleLruShmemSize();