Developing SQL Databases — Question 73

You use Microsoft SQL Server Profile to evaluate a query named Query1. The Profiler report indicates the following issues:
✑ At each level of the query plan, a low total number of rows are processed.
✑ The query uses many operations. This results in a high overall cost for the query.
You need to identify the information that will be useful for the optimizer.
What should you do?

Answer options

• A. Start a SQL Server Profiler trace for the event class Auto Stats in the Performance event category.
• B. Create one Extended Events session with the sqlserver.missing_column_statistics event added.
• C. Start a SQL Server Profiler trace for the event class Soft Warnings in the Errors and Warnings event category.
• D. Create one Extended Events session with the sqlserver.missing_join_predicate event added.

Correct answer: D

Explanation

The correct answer is D because the sqlserver.missing_join_predicate event can help identify missing join conditions that may be causing inefficient query execution. Options A and C do not directly address the specific issues related to the query plan and overall cost, while option B focuses on missing column statistics, which is not as relevant in this context.