The SQL Server Query Store page uses SQL Server Query Store data to analyze query performance history, plan changes, and resource usage over time.
Query Store requires SQL Server 2016 or later and must be supported and enabled for the database being analyzed. Mini DBA may show an unsupported message for editions or versions that do not support Query Store.
SQL Server Query Store keeps query performance history inside the database. That makes it valuable for regressions, plan changes, and before/after comparisons. Cached SQL tells you what is expensive now; Query Store helps show whether the query was always expensive, recently regressed, changed plans, or became expensive after a release.
When a Query Store query has multiple plans, use the plan buckets to identify the plan tied to the bad time range, then open the execution plan and compare expensive operators, warnings, missing index evidence, and parameter clues.
Use Query Store when investigating:
The SQL Server version or edition may not support Query Store, or Query Store may not be enabled for the database.
Query Store is database scoped. Mini DBA offers a server-level view for convenience and database-level Query Store pages when you want to focus on one database.
Use both. Query Store is better for history and regressions. Cached SQL is better for what is currently represented in plan cache.