Re: postgresql latency & bgwriter not doing its job

On 2014-08-31 01:50:48 +0300, Heikki Linnakangas wrote:

> If we're going to fsync between each file, there's no need to sort all the
> buffers at once. It's enough to pick one file as the target - like in my
> crude patch - and sort only the buffers for that file. Then fsync that file
> and move on to the next file. That requires scanning the buffers multiple
> times, but I think that's OK.

I really can't see that working out. Production instances of postgres
with large shared_buffers settings (say 96GB in one case) have tens of
thousands of relations (~34500 in the same case). And that's a database
with a relatively simple schema. I've seen much worse.