Query Store status for every database takes two queries, and the first is not enough. This post builds four demo databases, shows why the is_query_store_on flag hides frozen and read-only states, and runs one script that reads the real state of each database. It also shows what Query Store costs in memory.
Forcing a Plan in Query Store and Checking That It Held
Use forcing a plan in Query Store with verified IDs, then audit force failures and runtime results every week so the fix stays useful.
Canceled Query Plan: Three Ways to Capture It in SQL Server
A canceled query plan can be captured with Live Query Statistics, with a live plan query while the statement runs, or from Query Store after the cancel. This post runs a long query, reads its plan while it runs, cancels it and then reads the aborted run from Query Store. It also explains which plan each method returns.
Disable Query Store on an Always On Database: What Blocks It
To disable Query Store on an Always On database, run ALTER DATABASE with QUERY_STORE = OFF, and try OFF (FORCED) when the statement waits. This post shows the states to read, the background commands that block the statement and the steps used on an Always On database. It marks which parts were tested on a single server and which come from a client case.
Proving a Tuning Change Worked With Before and After Numbers
Prove a tuning change with before and after numbers from Query Store for CPU, reads, duration, and comparable execution volume.
Copy Database Without Statistics and Query Store Data
To copy database without statistics, add NO_STATISTICS and NO_QUERYSTORE to DBCC CLONEDATABASE. This post shows why that matters, because histograms and Query Store texts hold real values. It also shows the plan estimate that changes, how to make a clone writable, and what VERIFY_CLONEDB does.
Clone Database in SQL Server With DBCC CLONEDATABASE
Clone Database in SQL Server with DBCC CLONEDATABASE and you copy the structure and the statistics without a single row. This post runs the command on a demo database, checks what the clone holds and what it leaves out, and shows that the optimizer builds the same plan from the copied statistics.