Re: Why Wal_buffer is 64KB - Mailing list pgsql-performance

From Tadipathri Raghu
Subject Re: Why Wal_buffer is 64KB
Date
Msg-id 645d9d71003282300j6ef4a9d5pbfa257667e6a7e3a@mail.gmail.com
Whole thread Raw
In response to Re: Why Wal_buffer is 64KB  (Scott Marlowe <scott.marlowe@gmail.com>)
Responses Re: Why Wal_buffer is 64KB  (Scott Marlowe <scott.marlowe@gmail.com>)
Re: Why Wal_buffer is 64KB  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-performance
Hi All,
 
Thank you for all the support.
 
I have noticed one more thing here, that if you turn off the fsync and try to run the transaction than its breaking the currnet filenode and generating another filenode. Is it true that whenever you turn off or on the fsync the filenode will break and create one more on that table.
 
Regards
Raghavendra

On Fri, Mar 26, 2010 at 7:30 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
On Fri, Mar 26, 2010 at 7:43 AM, Pierre C <lists@peufeu.com> wrote:
>
>> After fsync/syncronous_commit off
>
> Do not use fsync off, it is not safe. Who cares about the performance of
> fsync=off, when in practice you'd never use it with real data.
> synchronnous_commit=off is fine for some applications, though.

There are situations where it's ok, when all the data are
reproduceable from other sources, etc.  for instance I have a
reporting server that is a slony slave that runs with fsync off.  If
it does crash and I can recreate the node in an hour or so and be back
online.  With fsync off the machine is too slow to do its job, and
it's not the primary repo of the real data, so it's ok there.

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