"yotsunaga.naoki@fujitsu.com" <yotsunaga.naoki@fujitsu.com> writes:
> I did the following.
> Even though I accessed one partition table(test2 table), I also acquired locks on other partition tables(test1
table).
> I expected to acquire locks on the parent table(test table) and the partition table to access(test2 table).
> Why does this happen?
You specified a generic plan:
> postgres=# set plan_cache_mode = force_generic_plan ;
so you are not going to get any plan-time optimization based on knowing
the id parameter. Therefore the plan must include sub-plan nodes for
every child table, so executing it requires locking all those tables
to make sure their schemas haven't changed.
regards, tom lane