Re: turning fsync off for WAL

On Mon, Jun 2, 2008 at 6:12 PM, Ram Ravichandran <ramkaka@gmail.com> wrote:
> Hey,
> I am running a postgresql server on Amazon EC2. My current plan is to mount
> an Amazon S3 bucket as a drive using PersistentFS which is a POSIX-compliant
> file system.
> I will be using this for write-ahead-logging. The issue with S3 is that
> though the actual storage is cheap, they charge $1 per 100,000 put requests
>  - so frequent fsyncs will
> cost me a lot.
> I've been talking to the makers of persistentFS, and one possible solution
> is for the file system to disobey fsyncs. I am trying to find out the
> implications of this method in
> case of a crash. Will I only lose information since the last fsync? Or will
> the earlier data, in general, be corrupted due to some out-of-order writes
> (I remember seeing this somewhere)?

Running without fsyncs is likely to lead to a corrupted db if you get
a crash / loss of connection etc...