Concepts
Query Store is a powerful feature in Azure SQL Database that allows you to monitor and manage the performance of your database queries. It helps you identify and troubleshoot performance issues, and provides valuable insights into query execution plans and resource usage. This article will guide you through the process of configuring Query Store in Azure SQL Database.
Enabling Query Store
To enable Query Store for your Azure SQL Database, you can use the following T-SQL statement:
ALTER DATABASE [database_name] SET QUERY_STORE = ON;
Replace [database_name] with the name of your database. Once executed, this statement enables Query Store and starts capturing query performance data.
Configuring Query Store Settings
Query Store has various settings that you can configure to suit your specific requirements. These settings include:
- Query Store Capture Mode:
- AUTO: Captures all queries, except those specified as system queries by Azure SQL Database.
- READ_WRITE: Pauses data capture during high-load periods to reduce overhead.
- OFF: Disables data capture.
To configure the capture mode, use the following T-SQL statement:
ALTER DATABASE [database_name] SET QUERY_STORE (OPERATION_MODE =); Replace
- Query Store Data Flush Interval:
The data flush interval determines how frequently Query Store writes data to disk. You can configure it using the following T-SQL statement:
ALTER DATABASE [database_name] SET QUERY_STORE (DATA_FLUSH_INTERVAL_SECONDS =); Replace
- Query Store Retention:
Query Store retains data for a specific duration, after which it is automatically purged. You can configure the retention period using the following T-SQL statement:
ALTER DATABASE [database_name] SET QUERY_STORE (CLEANUP_POLICY =); Replace
- OFF: Disables data retention.
- AUTO: Automatically purges data based on the configured size-based or time-based settings.
- INTERVAL: Purge data based on a specific time interval.
- STALE_QUERY_THRESHOLD_DAYS: Specify the number of days after which queries are considered stale and are purged.
Monitoring Query Performance
Once Query Store is enabled and configured, you can start monitoring query performance. There are several built-in reports and views available to help you analyze query performance data stored in Query Store.
To view the reports, you can use the following T-SQL statement:
-- Query Store Overview report
SELECT * FROM sys.query_store_runtime_stats;
-- Query Store Tracked Queries report
SELECT * FROM sys.query_store_plan;
-- Query Store Query Performance report
SELECT * FROM sys.query_store_query;
You can further customize the reports by adding filters and aggregations based on your specific requirements.
Summary
Configuring Query Store in Azure SQL Database is a crucial step in managing and optimizing query performance. By enabling and configuring Query Store, you gain valuable insights into query execution plans, resource usage, and performance metrics. This allows you to identify and resolve performance issues, leading to improved overall database performance.
Answer the Questions in Comment Section
The Query Store feature in Azure SQL Database allows you to monitor and analyze the performance of individual queries executed against your database.
– True
Which of the following metrics can be monitored using Query Store? (Select all that apply)
a) Average CPU time
b) Total number of rows affected by a query
c) Execution plan changes
d) Maximum memory usage
– All of the above
The Query Store captures query performance data and stores it for a fixed duration of time before it gets automatically purged.
– True
By default, the Query Store captures execution plans for every query executed against the database.
– False
Which of the following statements is true regarding configuring Query Store settings? (Select all that apply)
a) Query Store can only be enabled or disabled at the database level.
b) You can configure the data retention period for query data.
c) Query Store can be enabled or disabled for specific queries using query hints.
d) You can configure Query Store to capture execution plans for specific queries.
– b) You can configure the data retention period for query data.
c) Query Store can be enabled or disabled for specific queries using query hints.
In Azure SQL Database, how can you force an immediate purge of Query Store data?
a) Use the sys.sp_query_store_force_purge_data stored procedure.
b) Execute the ALTER DATABASE MODIFY QUERY_STORE CLEAR ALL statement.
c) Query Store data cannot be manually purged.
d) Use the sys.fn_purge_query_data function.
– b) Execute the ALTER DATABASE MODIFY QUERY_STORE CLEAR ALL statement.
The Query Store feature is available in which edition(s) of Azure SQL Database? (Select all that apply)
a) Basic
b) Standard
c) Premium
d) Managed Instance
– b) Standard
c) Premium
d) Managed Instance
Which system views can be queried to retrieve information about Query Store in Azure SQL Database? (Select all that apply)
a) sys.query_store_query
b) sys.query_store_plan
c) sys.query_store_runtime_stats
d) sys.query_store_plan_persist
– a) sys.query_store_query
b) sys.query_store_plan
c) sys.query_store_runtime_stats
The Query Store allows you to force a specific execution plan for a query.
– True
In Azure SQL Database, the Query Store can be used for performance troubleshooting and identifying regression in query performance over time.
– True
Great post! Can someone explain how to configure Query Store for an existing Azure SQL Database?
What’s the main advantage of using Query Store?
Thanks, very informative!
How does Query Store help in identifying issues with query performance?
This article was super helpful, thank you!
Can Query Store be used with on-premise SQL Server instances as well?
The steps to enable Query Store in the blog post are very clear!
I noticed a slight drop in performance after enabling Query Store. Is this normal?