Re: A couple of patches for PostgreSQL 64bit support

Koichi Suzuki <koichi@intellilink.co.jp> writes:
> Here're a couple of patches for PostgreSQL 64bit support.  There're just
> two extension to 64bit, size of shared memory and transaction ID.

I asked originally for some experimental evidence showing any value
in having more than 2Gb of shared buffers.  In the absence of any
convincing demonstration, I'm not very inclined to worry about whether
we can handle wider-than-int shared memory size.

As for the XID change, I don't think this patch accurately reflects the
size of the impact.  There are a lot of things that in practice need to
be the same size as XID (CID, most obviously, but I suspect also OID).
And again, some demonstration of the performance impact would be
appropriate.  Here, not only do you have to prove that widening XID
isn't a big performance hit in itself, but you also have to convince
us that it's a win compared to the existing approach of vacuuming at
least every billion transactions.

            regards, tom lane