Re: Question about concurrent synchronous and asynchronous commits - Mailing list pgsql-general

From Dan Birken
Subject Re: Question about concurrent synchronous and asynchronous commits
Date
Msg-id AANLkTik_MPnkuh63SDNGSncD5kYfD9ti406nD1PSZWNU@mail.gmail.com
Whole thread Raw
In response to Re: Question about concurrent synchronous and asynchronous commits  (Vick Khera <vivek@khera.org>)
Responses Re: Question about concurrent synchronous and asynchronous commits  (Vick Khera <vivek@khera.org>)
List pgsql-general
Ok given your response, this is my understanding of how the WAL works:

When you begin a transaction, all your changes write to the in-memory WAL buffer, and that buffer flushes to disk when:
a) Somebody commits a synchronous transaction
b) The WAL buffer runs out of space

Please correct me if I'm wrong.

-Dan

On Wed, Jan 12, 2011 at 12:32 PM, Vick Khera <vivek@khera.org> wrote:
On Wed, Jan 12, 2011 at 12:03 AM, Dan Birken <birken@gmail.com> wrote:
> If I commit asynchronously and then follow that with a synchronous commit,
> does that flush the asynchronous commit as well?

I'm pretty sure it does, because it has to flush the write-ahead log
to disk, and there's only one.  You can think of it as getting the
flush for free from the first transaction, since the single flush
covered the requirements of both transactions.

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

pgsql-general by date:

Previous
From: Ben Chobot
Date:
Subject: Re: Inconsistent time interval formatting
Next
From: Tom Lane
Date:
Subject: Re: Inconsistent time interval formatting