Assume that you use Microsoft SQL Server 2016 Always On Availability Groups. After statistics are updated by using the FULLSCAN option on the primary replica, the statistics on the secondary replica become stale or out-of-date. When you run a query on the secondary replica, a bad query plan might be used. This causes slow queries.
Article ID: 4016655 - Last Review: 20 Mar 2017 - Revision: 2