Re: 64-bit queryId?

Peter Geoghegan <pg@bowt.ie> writes:
> On Sat, Sep 30, 2017 at 7:34 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> Assuming, however, that you don't manage to prove all known
>> mathematics inconsistent, what one might reasonably hope to do is
>> render collisions remote enough that one need not worry about them too
>> much in practice.

> Isn't that already true in the case of queryId? I've never heard any
> complaints about collisions.

More to the point: with 32-bit IDs, it's apparent that you shouldn't
really rely on them being unique, and should design your usage so that
it will survive collisions.  Robert seems to be arguing that if we
merely made the IDs wider, it would be okay to design applications that
don't allow for that and would fail hard on a collision.  I'm reminded
of Weinberg's famous line "If builders built houses the way programmers
build programs, the first woodpecker to come along would destroy
civilization".

			regards, tom lane