Re: avoid MERGE_ACTION keyword?

On Thu, 16 May 2024 at 15:15, Peter Eisentraut <peter(at)eisentraut(dot)org> wrote:
>
> I wonder if we can avoid making MERGE_ACTION a keyword.
>

Yeah, there was a lot of back and forth on this point on the original
thread, and I'm still not sure which approach is best.

> I think we could parse it initially as a function and then transform it
> to a more special node later. In the attached patch, I'm doing this in
> parse analysis. We could try to do it even later and actually execute
> it as a function, if we could get the proper context passed into it somehow.
>

Whichever way it's done, I do think it's preferable to have the parse
analysis check, to ensure that it's being used in the right part of
the query, rather than leaving that to plan/execution time.

If it is turned into a function, the patch also needs to update the
ruleutils code --- it needs to be prepared to output a
schema-qualified function name, if necessary (something that the
keyword approach saves us from).

Regards,
Dean