Re: proposal: Set effective_cache_size to greater of .conf value, shared_buffers

Robert Haas <robertmhaas@gmail.com> writes:
> I basically think the auto-tuning we've installed for
> effective_cache_size is stupid.  Most people are going to run with
> only a few GB of shared_buffers, so setting effective_cache_size to a
> small multiple of that isn't going to make many more people happy than
> just raising the value - say from the current default of 128MB to, oh,
> 4GB - especially because in my experience queries aren't very
> sensitive to the exact value; it just has to not be way too small.  I
> bet the number of PostgreSQL users who would be made happy by a much
> higher hard-coded default is not too different from the number that
> will be made happy by the (completely unprincipled) auto-tuning.

There is a lot to be said for that argument, especially considering
that we're not even really happy with the auto-tuning mechanism,
never mind the behavior it's trying to implement.
        regards, tom lane