As a database administrator or developer, it is crucial to have insights into the performance of your SQL queries. The SQL Query Store, introduced in SQL Server 2016, is a powerful tool that helps you monitor and analyze the execution plans of your queries. In this blog post, we will explore how to effectively utilize the SQL Query Store to identify and resolve query performance issues.
Table of Contents
- Introduction
- Enabling the SQL Query Store
- Viewing Query Execution Plans
- Analyzing and Troubleshooting Query Performance
- Conclusion
Introduction
The SQL Query Store is a feature in SQL Server that captures query runtime information, including execution plans, for later analysis. This valuable data can help identify queries with performance degradation, query plan changes, and overall query workload patterns.
Enabling the SQL Query Store
To enable the SQL Query Store, you need to set the compatibility level of your database to 130 or higher. Once enabled, the Query Store starts capturing execution statistics for queries.
-- Enable Query Store on a database
ALTER DATABASE YourDatabase
SET QUERY_STORE = ON;
You can also configure the Query Store retention period and capture mode to suit your requirements.
Viewing Query Execution Plans
With the SQL Query Store enabled, you can easily view the execution plans for individual queries. Here’s an example of how to view the execution plan for a specific query:
-- Query Statement
SELECT * FROM Customers WHERE Country = 'USA';
-- View Query Execution Plan
SELECT q.query_id, qt.query_sql_text, qp.query_plan
FROM sys.query_store_query q
JOIN sys.query_store_query_text qt ON q.query_text_id = qt.query_text_id
JOIN sys.query_store_plan qpp ON q.last_plan_id = qpp.plan_id
JOIN sys.query_store_runtime_stats qr ON q.query_id = qr.query_id
JOIN sys.query_store_runtime_stats_interval qsrsi ON qr.runtime_stats_interval_id = qsrsi.runtime_stats_interval_id
WHERE qt.query_sql_text LIKE '%FROM Customers WHERE Country = ''USA''%'
ORDER BY qsrsi.start_time DESC;
In the above example, we retrieve the query ID, query text, and execution plan for a specific query. You can customize the query to filter results based on different criteria.
Analyzing and Troubleshooting Query Performance
The SQL Query Store enables you to analyze and troubleshoot query performance issues by providing various metrics and insights. Some key areas to focus on include:
- Execution Statistics: You can view metrics such as query duration, CPU time, and logical reads to identify queries with high resource usage.
- Query Plan Changes: The Query Store tracks plan regression by comparing the execution plans over time. You can identify plan changes and analyze the impact on query performance.
- Query Performance Insight: The Query Store provides graphical reports for analyzing query performance trends and identifying the top resource-consuming queries.
By leveraging the information provided by the SQL Query Store, you can optimize query execution plans, identify bottlenecks, and improve overall database performance.
Conclusion
The SQL Query Store is a powerful tool that enables database administrators and developers to monitor and analyze query execution plans. By leveraging the Query Store, you can troubleshoot query performance issues, identify plan regression, and optimize query execution. Take advantage of this feature to ensure optimal performance for your SQL queries.
#sql #query-store