Re: planner missing a trick for foreign tables w/OR conditions

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Tue, Dec 17, 2013 at 12:28 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> (I wonder if it'd be worth inserting a check that
>> there's not already a manually-generated equivalent clause, too ...)

> Sounds a little too clever IMHO.

The argument for doing it is that we might otherwise find ourselves
degrading the plans for previously-manually-optimized queries. On the
other hand, the existing index-driven code has probably forestalled the
need for many people to do that; at least, I don't recall seeing much
discussion of doing that sort of thing by hand.

I'm happy to leave the issue out of the first version of the patch,
anyway.

regards, tom lane