Re: short circuit suggestion in find_hash_columns()

On Fri, Jul 9, 2021 at 8:28 AM David Rowley <dgrowleyml(at)gmail(dot)com> wrote:

> On Sat, 10 Jul 2021 at 03:15, Zhihong Yu <zyu(at)yugabyte(dot)com> wrote:
> > I was looking at find_hash_columns() in nodeAgg.c
> >
> > It seems the first loop tries to determine the max column number needed,
> along with whether all columns are needed.
> >
> > The loop can be re-written as shown in the patch.
>
> This runs during ExecInitAgg(). Do you have a test case where you're
> seeing any performance gains from this change?
>
> David
>

Hi,
I made some attempt in varying related test but haven't seen much
difference in performance.

Let me spend more time (possibly in off hours) on this.

Cheers