On Wed, 9 Apr 2025 at 17:38, Amit Langote <amitlangote09@gmail.com> wrote:
> Still, maybe a tiny tweak to the last line could help steer readers
> right without diving into storage. How about:
>
> Most operations on EquivalenceClasses should ignore child members,
> which are stored separately from normal members.
I think the only part of the current text that makes me slightly
uncomfortable is the "ignore child members". I don't mind your text,
but it does introduce detail about how the members are stored, which
isn't there before.
I think the "ignore child members" part could be fixed with:
--- a/src/backend/optimizer/README
+++ b/src/backend/optimizer/README
@@ -902,7 +902,7 @@ 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.
+Most operations on EquivalenceClasses needn't look at child members.
Would that be ok?
David
