Re: PATCH: index-only scans with partial indexes

Hi,

At Thu, 25 Feb 2016 12:22:45 +0100, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> wrote in <56CEE405(dot)30108(at)2ndquadrant(dot)com>
> >> Attached is a v6 of the patch, which is actually the version
> >> submitted by Kyotaro-san on 2015/10/8 rebased to current master and
> >> with two additional changes.
> >
> > This relies on the fact I believe that no indexrelinfos are
> > shared among any two baserels. Are you OK with that?
>
> I'm not sure what this refers to? You mean the fact that an index will
> have one IndexOptInfo instance for each baserel? Yes, that seems fine
> to me.

Yes that what I meant.

> >> Firstly, I've removed the "break" from the initial foreach loop in
> >> check_partial_indexes(). As explained in the previous message, I
> >> believe this was a bug in the patch.
> >
> > I agreed. The break is surely a bug. (the regression didn't find
> > it though..)
> >
> >> Secondly, I've tried to improve the comments to explain a bit better
> >> what the code is doing.
> >
> > In check_partial_indexes, the following commnet.
> >
> >> /*
> >> * Update restrictinfo for this index by excluding clauses that
> >> * are implied by the index predicates. We first quickly check if
> >> * there are any implied clauses, and if we found at least one
> >> * we do the actual work. This way we don't need the construct
> >> * a copy of the list unless actually needed.
> >> */
> >
> > Is "need the construct" a mistake of "need to construct" ?
> >
> >
> > match_restriction_clauses_to_index is called only from
> > create_index_paths, and now the former doesn't use its first
> > parameter rel. We can safely remove the useless parameter.
> >
> > - match_restriction_clauses_to_index(RelOptInfo *rel, IndexOptInfo
> > - *index,
> > - IndexClauseSet *clauseset)
> > + match_restriction_clauses_to_index(IndexOptInfo *index,
> > + IndexClauseSet *clauseset)
> >
> > I find no other problem and have no objection to this. May I mark
> > this "Ready for committer" after fixing them?
>
> OK. Do you want me to do the fixes, or will you do that?

Ah. I will do. Please wait a minute.

regares,

--
Kyotaro Horiguchi
NTT Open Source Software Center