Re: [HACKERS] Skip all-visible pages during second HeapScan of CIC

On 3/7/17 9:42 PM, Pavan Deolasee wrote:
>
> Fair point. I'm not going to "persist" with the idea too long. It seemed
> like a good, low-risk feature to me which can benefit certain use cases
> quite reasonably. It's not uncommon to create indexes (or reindex
> existing indexes to remove index bloats) on extremely large tables and
> avoiding a second heap scan can hugely benefit such cases. Holding up
> the patch for something for which we don't even have a proposal yet
> seemed a bit strange at first, but I see the point.
>
> Anyways, for a recently vacuumed table of twice the size of RAM and on a
> machine with SSDs, the patched CIC version runs about 25% faster. That's
> probably the best case scenario.
>
> I also realised that I'd attached a slightly older version of the patch.
> So new version attached, but I'll remove the patch from CF if I don't
> see any more votes in favour of the patch.

I have marked this submission "Returned with Feedback".  Please feel 
free to resubmit to a future commitfest or open a discussion on hackers 
if you develop a new approach.

Thanks,
-- 
-David
david@pgmasters.net