On Thu, Dec 6, 2018 at 12:50 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > > If we called it at the start of every query, couldn't we dispense with > > the call in relation_openrv_extended()? > > No. You need to do AIM *after* obtaining the lock, else you still > have the race condition that you can execute a query on a table > without being aware of recent DDL on it.
Huh? The call in relation_openrv_extended() happens before acquiring the lock. > What we could possibly do to close the gap cited above is to have > plancache.c's CheckCachedPlan force an AIM call if it notices that > the plan it wants to re-use has a non-empty PlanInvalItems list. > If it does not, then there is nothing that AIM would cause invalidation > for anyway. This still leaves us with a query-duration-sized race > condition window for DDL on functions and domains, but not any larger > than that. That would be a nice place to get. Not perfect, but better than now. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
