Re: GTIN14 support for contrib/isn

čt 8. 6. 2023 v 17:20 odesílatel Michael Kefeder <mike(at)multiwave(dot)ch> napsal:
>
>
> Am 15.03.19 um 17:27 schrieb Tom Lane:
> > Michael Kefeder <mike(at)multiwave(dot)ch> writes:
> >> For a project of ours we need GTIN14 data type support.
> >
> > Hm, what is that and where would a reviewer find the specification for it?
> >
> specs are from GS1 here https://www.gs1.org/standards/id-keys/gtin
> side-note EAN13 is actually called GTIN-13 now. Wikipedia has a quick
> overview https://en.wikipedia.org/wiki/Global_Trade_Item_Number
>
> >> Looking at the code I saw every format that isn-extension supports is
> >> stored as an EAN13. Theoretically that can be changed to be GTIN14, but
> >> that would mean quite a lot of rewrite I feared, so I chose to code only
> >> GTIN14 I/O separetely to not interfere with any existing conversion
> >> magic. This yields an easier to understand patch and doesn't touch
> >> existing functionality. However it introduces redundancy to a certain
> >> extent.
> >
> > Yeah, you certainly don't get to change the on-disk format of the existing
> > types, unfortunately. Not sure what the least messy way of dealing with
> > that is. I guess we do want this to be part of contrib/isn rather than
> > an independent module, if there are sane datatype conversions with the
> > existing isn types.
> >
> the on-disk format does not change (it would support even longer codes
> it's just an integer where one bit is used for valid/invalid flag, did
> not touch that at all). Putting GTIN14 in isn makes sense I find and is
> back/forward compatible.
>
> >> Find my patch attached. Please let me know if there are things that need
> >> changes, I'll do my best to get GTIN support into postgresql.
> >
> > Well, two comments immediately:
> >
> > * where's the documentation changes?
> >
> > * simply editing the .sql file in-place is not acceptable; that breaks
> > the versioning conventions for extensions, and leaves users with no
> > easy upgrade path. What you need to do is create a version upgrade
> > script that adds the new objects. For examples look for other recent
> > patches that have added features to contrib modules, eg
> >
> > https://git.postgresql.org/gitweb/?p=postgresql.git&a=commitdiff&h=eb6f29141bed9dc95cb473614c30f470ef980705
> >
> > Also, I'm afraid you've pretty much missed the deadline to get this
> > into PG v12; we've already got more timely-submitted patches than
> > we're likely to be able to finish reviewing. Please add it to the
> > first v13 commit fest,
> >
> > https://commitfest.postgresql.org/23/
> >
> > so that we don't forget about it when the time does come to look at it.
> >
> > regards, tom lane
> >
>
> thanks for the feedback! will do mentioned documentation changes and
> create a separate upgrade sql file. Making it into v13 is fine by me.

Hello!

If I understand it well, this patch wasn't finished and submitted
after this discussion. If there is still interest, I can try to polish
the patch, rebase and submit. I'm interested in GTIN14 support.

> br
> mike
>
>
>