Re: [HACKERS] [PATCH] Overestimated filter cost and its mitigation

On Thu, Nov 9, 2017 at 12:33 PM, Ashutosh Bapat
<ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
> Looking at order_qual_clauses(), we can say that a set of quals q1
> .... qn are ordered the same irrespective of the set of clauses they
> are subset of. E.g. if {q1 .. qn} is subset of Q (ordered as Qo) and
> also Q' (ordered as Q'o) the order in which they appear in Qo and Q'o
> is same. So, even if different paths segregate the clauses in
> different set, within each set the order is same. FWIW, we can order
> all clauses in largest set once and use that order every time. Albeit
> we will have to remember the order somewhere OR make the separator
> routine retain the order in the larger set, which I guess is true
> about all separator functions.

I am not sure what to think about this patch, so moved to next CF. The
patch still applies. Hayamizu-san, it would be nice as well if you
could review other's patches. One patch reviewed for one patch
submitted, with equal difficulty. You should also get a community
account so as it is possible to add your name as an author of this
patch.
--
Michael