1. Go, go Query Store!
Gail Shaw

2. The Query what? New in SQL 2016 / Azure db version 12
A ‘flight recorder’ for SQL Server queries
Aggregated performance information and execution plan
Persisted into the database

3. What magic is this?
On compilation, the query and plan are stored in the Query Store
When a query is recompiled, the new plan is sent to the Query Store
If it’s a different plan to ones already in the Query Store, it’s added
When query execution completes, run-time info is sent to the Query Store
Data is written to disk in 15-minute intervals (configurable)
Run time stats are aggregated, default 60 minutes

4. But, we’ve already got DMVs
The run-time DMVs depend on a query having a plan in cache
They don’t record queries run with any recompile setting
They’re memory only.
Query Store is persisted into the user database
Doesn’t rely on plans still being in cache
Is included in backups!

5. Ok, so how do I use it? SSMS 2016 has reports built in
Or, lots of catalogue views
sys.query_store_query
sys.query_store_query_text
sys.query_store_plan
sys.query_store_runtime_stats
sys.query_store_runtime_stats_interval

6. Uses for Query Store Upgrade tests
Identify cases of parameter sniffing or other unstable plan problems
Pinpoint the top resource consuming queries, without needing SQLTrace/XE

7. Further resources
Monitoring performance using the Query Store -
How the Query Store collects data - us/library/mt aspx
recorder-for-your-database/