Microsoft · DP-300
Indexes, queries, and execution plans
DP-300 · Lesson 13 of 22 · 1:52:06
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In this lesson
Prepare for the DP-300 exam (Administering Microsoft Azure SQL Solutions). In this lesson: clustered, nonclustered, covering, and missing indexes, query constructs that prevent index seeks, reading estimated, actual, and live execution plans (key lookups, scans, spills, and estimate gaps), Intelligent Insights, and a tuning method that measures every change. Includes three original practice questions.
Preview the topics
- Contoso’s query filters with WHERE YEAR(FilledOn) = 2026, and the plan shows a scan of the whole table, although an index exists on FilledOn. What should the developer change?
- Contoso’s actual plan shows an index seek on Stock, followed by a key lookup executed 50,000 times, for two columns. What change removes the lookups?
- Contoso’s procedure declares its parameter as nvarchar(20), while the ProductCode column is varchar(20), and the plan shows a scan with a warning. What’s the fix?