Re: mount -o async - is it safe?

Shane Wright <shane(dot)wright(at)edigitalresearch(dot)com> writes:

> Actually I thought that *all* the database had to have fsync() work correctly;
> not for integrity on failed transactions, but to maintain integrity during
> checkpointing as well. But I could well be wrong!

I think you're write, but what I was thinking of is the scenario where
WAL writes are done in small increments, then committed with fsync()
once a full page has been written. With a sync mount this would
result in the equivalent of fsync() for every small write, which would
hurt a lot.

I dimly recall this sort of thing being discussed in the past, but I
don't know offhand whether PG does its WAL writes in small chunks or
page-at-a-time.

-Doug