Re: Aggregate versions of hashing functions (md5, sha1, etc...)

On Fri, Jul 11, 2025, 18:27 Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com> wrote:

> On 7/11/25 01:49, Dominique Devienne wrote:
> > On Thu, Jul 10, 2025 at 6:25 PM Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
> wrote:
> >> On 7/10/25 04:48, Dominique Devienne wrote:
> >>> Seems so logical to me, that these hashing functions were available
> >>> are aggregates, I can't be the first one to think of that, can it?
> >>
> >> I've been on this list since late 2002 and I don't recall this ever
> >> being brought up. Now it is entirely possible that age has dimmed my
> >> recall abilities:) Though a quick search seems to confirm my memory.
> >
> > Hi. Given that [SQLite's SHA3 hasher][1] has it (OK, for [8 months
> only][2]),
> > it's hardly an original idea. And when considering that `sha3_query`
> > (and `sha1_query` before it) have been there for years, and provide
> > equivalent functionality, again, this is not novel by any stretch of
> > the imagination.
>
> Even if there was interest in writing the code, given that Postgres 18
> is in Beta I don't see this happening for it's release. That means the
> earliest it would arrive would be Fall of 2026. The alternative would be
> to do like Sqlite and create an extension that incorporates the code.
>

That's an ideal use case for an extension indeed .

@Dominique I'd suggest searching for these function on GitHub, just in case
there are already implementations out there.
I've seen a lot of weird aggregates out there for niche cases.

If not, it might be an interesting weekend project for me to explore.

>