x86-64 and PostgreSQL

From: Ron Johnson <ron(dot)l(dot)johnson(at)cox(dot)net>
To: PgSQL Performance ML <pgsql-performance(at)postgresql(dot)org>
Subject: x86-64 and PostgreSQL
Date: 2003-01-18 05:29:25
Message-ID: 1042867764.889.181.camel@haggis
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Hi,

Will there be any advantages to running Pg on a 64-bit CPU rather
than 32-bit?

The recent discussions in the "7.3.1 New install, large queries are
slow" thread make me think not, since Pg says that the OS can manage
buffers better:
<QUOTE From="Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>">
Yeah, but isn't that theory a hangover from pre-Unix operating systems?
In all modern Unixen, you can expect the kernel to make use of any spare
RAM for disk buffer cache --- and that behavior makes it pointless for
Postgres to try to do large amounts of its own buffering.

Having a page in our own buffer instead of kernel buffer saves a context
swap to access the page, but it doesn't save I/O, so the benefit is a
lot less than you might think. I think there's seriously diminishing
returns in pushing shared_buffers beyond a few thousand, and once you
get to the point where it distorts the kernel's ability to manage
memory for processes, you're really shooting yourself in the foot.
</QUOTE>

Also, would int8 then become a more "natural" default integer, rather
than the int4 that all of us millions of i386, PPC & Sparc users use?

Thanks,
Ron
--
+------------------------------------------------------------+
| Ron Johnson, Jr. mailto:ron(dot)l(dot)johnson(at)cox(dot)net |
| Jefferson, LA USA http://members.cox.net/ron.l.johnson |
| |
| "Basically, I got on the plane with a bomb. Basically, I |
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| the plane." |
| RICHARD REID, who tried to blow up American Airlines |
| Flight 63 |
+------------------------------------------------------------+

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