On 4/9/25 04:05, Richard Guo wrote:
On Tue, Apr 8, 2025 at 11:12 PM Dean Rasheed <dean.a.rash...@gmail.com> wrote:
On Tue, 8 Apr 2025 at 12:31, Andrei Lepikhov <lepi...@gmail.com> wrote:
Perhaps the way to do it is to make ChangeVarNodesExtended() take a
callback function to be invoked for each node visited. The callback
(which would then be in the planner, with the other SJE code) would do
any special handling it needed (for RangeTblRef and RestrictInfo
nodes), and call ChangeVarNodes_walker() for any other types of node,
to get the default behaviour.
Yeah, this might be a better approach. Perhaps we can borrow some
ideas from replace_rte_variables.
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?
[1] https://www.postgresql.org/message-id/3622801.1715010885%40sss.pgh.pa.us
--
regards, Andrei Lepikhov
