Re: patch: function xmltable

2017-01-25 15:07 GMT+01:00 Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>:

> Tom Lane wrote:
> > Andres Freund <andres(at)anarazel(dot)de> writes:
> > > On 2017-01-24 21:32:56 -0300, Alvaro Herrera wrote:
> > >> XMLTABLE is specified by the standard to return multiple rows ... but
> > >> then as far as my reading goes, it is only supposed to be supported in
> > >> the range table (FROM clause) not in the target list. I wonder if
> > >> this would end up better if we only tried to support it in RT. I
> asked
> > >> Pavel to implement it like that a few weeks ago, but ...
> >
> > > Right - it makes sense in the FROM list - but then it should be an
> > > executor node, instead of some expression thingy.
> >
> > +1 --- we're out of the business of having simple expressions that
> > return rowsets.
>
> Well, that's it. I'm not committing this patch against two other
> committers' opinion, plus I was already on the fence about the
> implementation anyway. I think you should just go with the flow and
> implement this by creating nodeTableexprscan.c. It's not even
> difficult.
>

I am playing with this and the patch looks about 15kB longer - just due
implementation basic scan functionality - and I didn't touch a planner.

I am not happy from this - still I have a feeling so I try to reimplement
reduced SRF.

Regards

Pavel

>
> --
> Álvaro Herrera https://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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