Avoid recomputing PlanProperties redundently #19796
Description
Is your feature request related to a problem or challenge?
We are trying to make planning faster. One significant cost of planning Physical (ExecutionPlans) is the time spent computing PlanProperties
for example with this benchmark
cargo bench --profile=profiling --bench sql_planner -- physical_plan_clickbench_q7
While reviewing #19462 from @askalt , we discussed the idea of optimizing certain parts of planning (for example ExecutionPlan::with_new_children) to avoid re-calculating the PlanProperties unecessairly)
See the conversation starting here #19462 (comment)
Describe the solution you'd like
I would like to find some way to avoid recomputing plan properties except when it is necessary
Describe alternatives you've considered
No response
Additional context
Somewhat blocked on