Re: Gin index on array of uuid

What's a good source code entry point to review how this is working for
anyarray currently? I am new to the postgres code. I spend some time
looking for it but all I found is the following (which I have not been able
to decipher yet).

[image: pasted1]

Thank you,
Enrique

On Tue, Jun 21, 2016 at 12:20 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Enrique MailingLists <enrique(dot)mailing(dot)lists(at)gmail(dot)com> writes:
> > Currently creating an index on an array of UUID involves defining an
> > operator class. I was wondering if this would be a valid request to add
> as
> > part of the uuid-ossp extension? This seems like a reasonable operator to
> > support as a default for UUIDs.
>
> This makes me itch, really, because if we do this then we should logically
> do it for every other add-on type.
>
> It seems like we are not that far from being able to have just one GIN
> opclass on "anyarray". The only parts of this declaration that are
> UUID-specific are the comparator function and the storage type, both of
> which could be gotten without that much trouble, one would think.
>
> > Any downsides to adding this as a default?
>
> Well, it'd likely break things at dump/reload time for people who had
> already created a competing "default for _uuid" opclass manually. I'm not
> entirely sure, but possibly replacing the core opclasses with a single one
> that is "default for anyarray" could avoid such failures. We'd have to
> figure out ambiguity resolution rules.
>
> regards, tom lane
>