From: Tom Lane <tgl@sss.pgh.pa.us>
To: shridhar@frodo.hserus.net
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: [pgsql-hackers-win32] Sync vs. fsync during checkpoint
Date: Thu, 05 Feb 2004 11:22:00 -0500
Message-ID: <3593.1075998120@sss.pgh.pa.us> (raw)
In-Reply-To: <200402052045.48448.shridhar@frodo.hserus.net>
References: <46C15C39FEB2C44BA555E356FBCD6FA49620A3@m0114.s-mxs.net>
<2297.1075992889@sss.pgh.pa.us>
<200402052045.48448.shridhar@frodo.hserus.net>
Shridhar Daithankar <shridhar@frodo.hserus.net> writes:
> There are other benefits of writing pages earlier even though they might not
> get synced immediately.
Such as?
> It would tell kernel that this is latest copy of updated buffer. Kernel VFS
> should make that copy visible to every other backend as well. The buffer
> manager will fetch the updated copy from VFS cache next time. All without
> going to disk actually..(Within the 30 seconds window of course..)
This seems quite irrelevant given the way we handle shared buffers.
> frequent fsyncs or frequent fsyncs per file descriptor written? I thought it
> was later.
You can only fsync one FD at a time (too bad ... if there were a
multi-file-fsync API it'd solve the overspecified-write-ordering issue).
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, shridhar@frodo.hserus.net
Subject: Re: [pgsql-hackers-win32] Sync vs. fsync during checkpoint
In-Reply-To: <3593.1075998120@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox