On Mon, Oct 12, 2020 at 04:07:30PM -0400, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > On Mon, Oct 12, 2020 at 02:26:15PM -0400, Tom Lane wrote:
> >> Yeah, I agree --- a version number is the wrong way to think about this.
>
> > The version number was to invalidate _all_ query hashes if the
> > algorithm is slightly modified, rather than invalidating just some of
> > them, which could lead to confusion.
>
> Color me skeptical as to the use-case for that. From users' standpoints,
> the hash is mainly going to change when we change the set of parse node
> fields that get hashed. Which is going to happen at every major release
> and no (or at least epsilon) minor releases. So I do not see a point in
> tracking an algorithm version number as such. Seems like make-work.
OK, I came up with the hash idea only to address one of your concerns
about mismatched hashes for algorithm improvements/changes. Seems we
might as well just document that cross-version hashes are different.
--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EnterpriseDB https://enterprisedb.com
The usefulness of a cup is in its emptiness, Bruce Lee