Thread: 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 ------ REL_14_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/f94edb06ab60545a0e9e90aedc39e3b81b2b9e3f 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(-)
On Wed, 24 Nov 2021 at 14:57, David Rowley <drowley@postgresql.org> wrote: > Flush Memoize cache when non-key parameters change I'm currently looking into why the buildfarm does not like this. David
On Wed, 24 Nov 2021 at 17:31, Michael Paquier <michael@paquier.xyz> wrote: > From what I can see, there are two separate problems here: > - force_parallel_mode = regress. > - -DRELCACHE_FORCE_RELEASE and/or -DCATCACHE_FORCE_RELEASE. Thanks. I missed adding keyparamids to the copy/read/write functions. David
On Wed, 24 Nov 2021 at 20:27, David Rowley <dgrowleyml@gmail.com> wrote: > > On Wed, 24 Nov 2021 at 17:31, Michael Paquier <michael@paquier.xyz> wrote: > > From what I can see, there are two separate problems here: > > - force_parallel_mode = regress. > > - -DRELCACHE_FORCE_RELEASE and/or -DCATCACHE_FORCE_RELEASE. > > Thanks. I missed adding keyparamids to the copy/read/write functions. Looks like the cause of the animals that had the plan change [1][2] is a timing issue where tenk2 is not auto-analyzed before the Memoize test. Due to the lack of stats, Memoize is not considered in the planner. I see tenk1 is manually ANALYZEd, so I'll just change the tests to use tenk1 instead of tenk2. David [1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=serinus&dt=2021-11-24%2002%3A04%3A18 [2] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=flaviventris&dt=2021-11-24%2002%3A24%3A03