The Plan Comparison menu option allows side-by-side comparison of two different execution plans, for easier identification of similarities and changes that explain the different behaviors for all the reasons stated above.
This option can compare between:
Two previously saved execution plan files (.sqlplan extension).
One active execution plan and one previously saved query execution plan.
Two selected query plans in Query Store.
Basic Concept: This question tests database auditing and query visibility. DP-300 expects you to distinguish between collecting audit events, retaining logs, and analyzing query behavior.
Why C is Correct: Save the actual execution plan. is related to operational monitoring or tuning, but it must match the exact signal needed: query history, resource utilization, wait/blocking detail, or automatic remediation. The scenario asks for: You need to compare the previous actual execution plan for the query to the Live Query Statistics. That makes Save the actual execution plan. the option that satisfies the required Azure SQL layer and operational outcome.
Why A is Wrong: Query Store captures query text, plans, and runtime statistics, making it central for reviewing query history and troubleshooting plan regressions. It does not expose the required metric, query history, wait/blocking signal, or tuning mechanism; using it would not give the administrator the evidence requested.
Why B is Wrong: Run the SET SHOWPLAN_ALL Transact-SQL statement. is related to operational monitoring or tuning, but it must match the exact signal needed: query history, resource utilization, wait
/blocking detail, or automatic remediation. It is useful in other troubleshooting paths, but this scenario requires a more specific monitoring or optimization feature.
Why D is Wrong: Query Store captures query text, plans, and runtime statistics, making it central for reviewing query history and troubleshooting plan regressions. It does not expose the required metric, query history, wait/blocking signal, or tuning mechanism; using it would not give the administrator the evidence requested.