Defer/async cache validation at start up? #513
Description
Whenever a server using RelStorage is being started it validates the local cache against the database, as it can be seen on the following log line:
2025-02-28 17:26:31,649 INFO [relstorage.cache.mvcc:525][MainThread] Polling 160420 oids stored in cache with SQL timeout None
Unfortunately, that can be veeeeeeery slow, leading to very slow start up, or worse, having a website downtime because all servers (as, e.g. you deploy a new update) are being restarted.
Could this validation be done asynchronously? Would that be a problem for running queries while these 160k objects are being validated?