pgsql: Flush Memoize cache when non-key parameters change

Flush Memoize cache when non-key parameters change

It's possible that a subplan below a Memoize node contains a parameter
from above the Memoize node. If this parameter changes then cache entries
may become out-dated due to the new parameter value.

Previously Memoize was mistakenly not aware of this. We fix this here by
flushing the cache whenever a parameter that's not part of the cache
key changes.

Bug: #17213
Reported by: Elvis Pranskevichus
Author: David Rowley
Discussion: https://postgr.es/m/17213-988ed34b225a2862@postgresql.org
Backpatch-through: 14, where Memoize was added

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/1050048a315790a505465bfcceb26eaf8dbc7e2e

Modified Files
--------------
src/backend/executor/nodeMemoize.c | 38 ++++++++++++++++++++++++++++++++
src/backend/nodes/bitmapset.c | 2 ++
src/backend/optimizer/plan/createplan.c | 10 ++++++---
src/backend/optimizer/util/clauses.c | 31 ++++++++++++++++++++++++++
src/include/nodes/execnodes.h | 2 ++
src/include/nodes/plannodes.h | 1 +
src/include/optimizer/clauses.h | 2 ++
src/test/regress/expected/memoize.out | 39 +++++++++++++++++++++++++++++++++
src/test/regress/sql/memoize.sql | 20 +++++++++++++++++
9 files changed, 142 insertions(+), 3 deletions(-)