The current TODO list has:
* Flush cached query plans when the dependent objects change,
when the cardinality of parameters changes dramatically, or
when new ANALYZE statistics are available
A more complex solution would be to save multiple plans for different
cardinality and use the appropriate plan based on the EXECUTE values.
* Track dependencies in function bodies and recompile/invalidate
This is particularly important for references to temporary tables
in PL/PgSQL because PL/PgSQL caches query plans. The only workaround
in PL/PgSQL is to use EXECUTE. One complexity is that a function
might itself drop and recreate dependent tables, causing it to
invalidate its own query plan.
Which of these are done or not done?