The Query Store is one of the biggest enhancements to the SQL Server 2016 database engine that will complete the performance tuning toolbox of database administrators and simplifies identification of performance outliers, manages execution plan regression, and allows for easier upgrades between versions of SQL Server. The query store also acts as a flight data recorder for the database, capturing query run-time statistics and providing a dashboard to sort queries by resource consumption.
The query store is extremely helpful, but it does require some management. We must enable it on each user database individually and need to change the space allocated to the query store from the default of 100 MB per database. We can use Query Store in all databases without concerns, in even densely packed pools.