Re: POC: Sharing record typmods between backends

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Sat, Aug 12, 2017 at 11:30 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>> That seems to involve a lot more than this though, given that currently
>> the stats collector data doesn't entirely have to be in memory. I've
>> seen sites with a lot of databases with quite some per-database stats
>> data. Don't think we can just require that to be in memory :(

> Hmm. I'm not sure it wouldn't end up being *less* memory. Don't we
> end up caching 1 copy of it per backend, at least for the database to
> which that backend is connected? Accessing a shared copy would avoid
> that sort of thing.

Yeah ... the collector itself has got all that in memory anyway.
We do need to think about synchronization issues if we make that
memory globally available, but I find it hard to see how that would
lead to more memory consumption overall than what happens now.

regards, tom lane