On Fri, Dec 2, 2016 at 8:41 AM, Andres Freund <andres@anarazel.de> wrote:
On 2016-11-30 16:11:23 +0530, Dilip Kumar wrote: > On Tue, Nov 29, 2016 at 11:21 PM, Robert Haas <robertmhaas@gmail.com> wrote: > > On Mon, Nov 28, 2016 at 11:17 PM, Dilip Kumar <dilipbalaut@gmail.com> wrote: > >> Actually we want to call slot_getattr instead heap_getattr, because of > >> problem mentioned by Andres upthread and we also saw in test results. > > > > Ah, right. > > > >> Should we make a copy of HeapKeyTest lets say ExecKeyTest and keep it > >> under executor ? > > > > Sure. > > I have worked on the idea you suggested upthread. POC patch is > attached.
Hm. I'm more than a bit doubful about this approach. Shouldn't we just *always* do this as part of expression evaluation, instead of special-casing for seqscans?
I.e. during planning recognize that an OpExpr can be evaluated as a scankey and then emit different qual evaluation instructions? Because then the benefit can be everywhere, instead of just seqscans.
I'll post my new expression evaluation stuff - which doesn't do this atm, but makes ExecQual faster in other ways - later this week. If we could get the planner (or parse-analysis?) to set an OpExpr flag that signals that the expression can be evaluated as a scankey, that'd be easy.