Re: Use of "long" in incremental sort code

David Rowley <dgrowleyml(at)gmail(dot)com> writes:
> I noticed the incremental sort code makes use of the long datatype a
> few times, e.g in TuplesortInstrumentation and
> IncrementalSortGroupInfo. (64-bit windows machines have sizeof(long)
> == 4). I understand that the values are in kilobytes and it would
> take 2TB to cause them to wrap. Never-the-less, I think it would be
> better to choose a better-suited type. work_mem is still limited to
> 2GB on 64-bit Windows machines, so perhaps there's some argument that
> it does not matter about fields that related to in-memory stuff, but
> the on-disk fields are wrong. The in-memory fields likely raise the
> bar further for fixing the 2GB work_mem limit on Windows.

> Maybe Size would be better for the in-memory fields and uint64 for the
> on-disk fields?

There is a fairly widespread issue that memory-size-related GUCs and
suchlike variables are limited to represent sizes that fit in a "long".
Although Win64 is the *only* platform where that's an issue, maybe
it's worth doing something about. But we shouldn't just fix the sort
code, if we do do something.

(IOW, I don't agree with doing a fix that doesn't also fix work_mem.)

regards, tom lane