Re: [PoC] Reducing planning time when tables have many partitions - Mailing list pgsql-hackers

Hi David,

On Wed, Apr 9, 2025 at 5:12 AM David Rowley <dgrowleyml@gmail.com> wrote:
> On Wed, 9 Apr 2025 at 02:24, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >
> > David Rowley <dgrowleyml@gmail.com> writes:
> > > I've pushed the patch now. Thanks for all the reviews of my adjustments.
> >
> > Shouldn't the CF entry be marked committed?
>
> I've done that now.

Should the following paragraph in src/backend/optimizer/README be
updated to reflect the new reality after recent changes?

    An EquivalenceClass can contain "em_is_child" members, which are copies
    of members that contain appendrel parent relation Vars, transposed to
    contain the equivalent child-relation variables or expressions. These
    members are not full-fledged members of the EquivalenceClass and do not
    affect the class's overall properties at all. They are kept only to
    simplify matching of child-relation expressions to EquivalenceClasses.
    Most operations on EquivalenceClasses should ignore child members.

The part about these being in the EquivalenceClass might be worth
rewording now that we keep them in a separate array.

--
Thanks, Amit Langote