On 4/10/25 13:36, Alexander Korotkov wrote:
On Wed, Apr 9, 2025 at 10:39 AM Andrei Lepikhov <lepi...@gmail.com> wrote:
It seems we are coming to the conclusion that join removal optimisation
may do something out of ChangeVarNodes resposibility. Before further
complicating of this function code I would like to know opinion of Tom,
who initially proposed [1] to use this routine. May be better a) return
to more specialised change_relid / sje_walker machinery or b) move
ChangeVarNodes out of rewriteManip and make it multi-purpose routine,
allowing to transform expression that may happen after a Var node change?
What about adding a callback to ChangeVarNodes_context that would
called for each RestrictInfo after changing varnodes itself? SJE
could use a callback that replaces OpExpr with NullTest when needed.
I think it is doable, of course. Just looking forward a little, it may
need more complication in the future (SJE definitely should be widened
to partitioned tables) and it may be simpler to have two different
routines for two different stages of planning.
--
regards, Andrei Lepikhov
