On 2018-Dec-15, Michael Paquier wrote: > On Fri, Dec 14, 2018 at 11:06:32PM -0300, Alvaro Herrera wrote: > > I did propose in my OP the idea of a PGPROC boolean flag that indicates > > whether the temp namespace has been set up. If not, have autovac remove > > those tables. I like this option better, but I fear it adds more > > ProcArrayLock contention. Maybe I can just use a new LWLock to > > coordinate that particular member of the ProcGlobal array ... (but then > > it can no longer be a boolean.) > > Isn't that what tempNamespaceId can be used for in PGPROC now? The flag > would be set only when a backend creates a new temporary schema so as it > can be tracked as the owner of the schema.
Oh, we already have it! Sorry, I overlooked it. With that, it seems the patch is fairly simple ... I wonder about the locking implications in autovacuum, though -- the value is set in backends without acquiring a lock. I wonder if we could use memory barriers, so it'd incur little cost. I wonder how this thing works in parallel query workers. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
