Re: Do we support using agg or window functions in delete statement?

Thanks a lot for reply.

2017-01-11 20:46 GMT+08:00 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> =?UTF-8?B?6auY5aKe55Cm?= <pgf00a(at)gmail(dot)com> writes:
> > In transformDeleteStmt:
>
> > qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
> > qry->hasAggs = pstate->p_hasAggs;
> > if (pstate->p_hasAggs)
> > parseCheckAggregates(pstate, qry);
>
> > Do we support using agg or window function in delete statement?
> > Or, this code should be removed?
>
> I think it's dead code given the syntactic limitations on DELETE,
> but I would not be in favor of removing it. Better to have it there to
> keep transformDeleteStmt looking as much as possible like the other ones.
> It's not like that's either expensive or a lot of code.
>

At present, only transformSelectStmt and transformSetOperationStmt
has parseCheckAggregates. All other transformXXXStmt don't contain it.

This inconsistency makes me have the question at the first mail.
I think it maybe better to do something.

>
> An example of why this would be penny-wise and pound-foolish is that
> we might choose to apply the check that you can't write aggregates in
> DELETE inside parseCheckAggregates. (We don't, but it's not an impossible
> future restructuring.)
>
> regards, tom lane
>

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