Re: Running PostgreSQL as fast as possible no matter the consequences

On Tue, Jan 25, 2011 at 5:32 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> Robert Haas wrote:
>> On Wed, Jan 19, 2011 at 12:07 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:

>> > ? ? ? ?http://developer.postgresql.org/pgdocs/postgres/non-durability.html
>>
>> This sentence looks to me like it should be removed, or perhaps clarified:
>>
>>     This does affect database crash transaction durability.
>
> Uh, doesn't it affect database crash transaction durability?  I have
> applied the attached patch to clarify things.  Thanks.

I think the point that was trying to be made there was that the other
parameters only lose and corrupt data when the machine crashes.
Synchronous commit turned off will lose data on a mere postgresql
server crash, it doesn't require a machine-level crash to cause data
loss.

Indeed, the currently committed doc is quite misleading.

" The following are configuration changes you can make
to improve performance in such cases; they do not invalidate
commit guarantees related to database crashes, only abrupt operating
system stoppage, except as mentioned below"

We've now removed the thing being mentioned below, but did not remove
the promise we would be mentioning those things.

Cheers,

Jeff