Re: FETCH FIRST clause WITH TIES option

Hi Alvaro,
On Fri, Sep 6, 2019 at 1:52 AM Alvaro Herrera from 2ndQuadrant <
alvherre(at)alvh(dot)no-ip(dot)org> wrote:

> As Tom just said in the thread for PERCENT, the gram.y changes need a
> better representation. Also, rename EXACT_NUMBER, per that thread.
>
> As far as I can tell, this concerns feature F867. I think we should
> mark that as supported after this patch -- please edit
> src/backend/catalog/sql_features.txt.
>

ok

>
> Earlier in the thread, Tomas Vondra said:
>
> > 3) I'm a bit confused by the initialization added to ExecInitLimit. It
> > first gets the tuple descriptor from the limitstate (it should not do
> so
>
> > directly but use ExecGetResultType). But when it creates the extra
> slot,
>
> > it uses ops extracted from the outer plan. That's strange, I guess ...
>
>
> >
>
>
> > And then it extracts the descriptor from the outer plan and uses it
> when
>
> > calling execTuplesMatchPrepare. But AFAIK it's going to be compared to
>
>
> > the last_slot, which is using a descriptor from the limitstate.
>
>
> >
>
>
> > IMHO all of this should use descriptor/ops from the outer plan, no? It
>
>
> > probably does not change anything because limit does not project, but
> it
>
> > seems confusing.
>
>
>
> and you replied:
>
> > agree
>
> ... yet this doesn't appear to have resulted in any change in the code,
> or I just missed it. Are you going to update the patch per that?
>
>
Its already done in v9 of the patch attached by Tomas

regards
Surafel