On 2016-10-25 13:18:47 -0400, Tom Lane wrote: > (Frankly, I'm pretty skeptical of this entire patch being worth the > trouble...)
The gains are quite noticeable in some cases. So if we can make it work without noticeable downsides... What I'm worried about though is that this, afaics, will quite noticeably *increase* total cost in cases with a noticeable number of columns and a not that selective qual. The reason for that being that HeapKeyTest() uses heap_getattr(), whereas upper layers use slot_getattr(). The latter "caches" repeated deforms, the former doesn't... That'll lead to deforming being essentially done twice, and it's quite often already a major cost of query processing. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
