On Wed, May 9, 2012 at 8:43 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Wed, May 9, 2012 at 10:34 AM, Bruce Momjian <bruce@momjian.us> wrote:
>>> It does provide an additional guarantee, but I accept you personally
>>> may not find that useful.
>>
>> The guarantee is that if Postgres crashes, we don't lose any data, but
>> not if the OS crashes (right?) because that isn't clear now.
>
> True, point taken.
Back when synchronous_commit only had 2 values, I thought it should
have had 3. The guarantee of losing transactions only on an OS crash,
and not on a Postgres server crash, seems quite valuable (especially
if you are playing around with custom extensions that might crash
Postgres upon custom bugs). And the costs seem minimal. If the
kernel is so constipated that even simple writes are blocking, it
seems you are hosed regardless of where those writes are occurring.
Cheers,
Jeff
