As a SQL Server enthusiast, I often find myself diving into the depths of the SQL Server documentation, always discovering new and exciting features. Today, I stumbled upon a system catalog view called sys.dm_exec_query_optimizer_info, and I couldn’t wait to share it with you all.
Before we delve into the details, I want to emphasize the importance of community development. If you have come across any interesting SQL Server concepts or features, please share them in the comments below. Together, we can expand our knowledge and help each other grow.
So, let’s talk about sys.dm_exec_query_optimizer_info. This view provides detailed statistics about the operation of the SQL Server query optimizer. It can be incredibly useful when tuning a workload to identify query optimization problems or improvements.
For example, you can use the total number of optimizations, the elapsed time value, and the final cost value to compare the query optimizations of the current workload and any changes observed during the tuning process.
The result set of a query against sys.dm_exec_query_optimizer_info will contain three columns:
- counter – Name of the optimizer statistics event.
- occurrence – Number of occurrences of the optimization event for this counter. This indicates how many times the counter specified in the counter column has been optimized.
- value – Average property value per event occurrence.
It’s fascinating to explore the inner workings of the query optimizer and gain insights into its behavior. By leveraging sys.dm_exec_query_optimizer_info, you can gain a deeper understanding of how your queries are being optimized and identify areas for improvement.
Remember, all occurrence values are cumulative and are reset to 0 at system restart. Similarly, all values for the value fields are set to NULL at system restart.
I hope you find sys.dm_exec_query_optimizer_info as intriguing as I did. If you have any questions or would like to share your experiences with this view, please leave a comment below. Let’s continue our journey of learning and discovery together!
Stay tuned for more exciting SQL Server concepts and ideas in future blog posts.