From the course: SQL Server Performance for Developers
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How to read an execution plan - SQL Server Tutorial
From the course: SQL Server Performance for Developers
How to read an execution plan
- [Instructor] Let's talk about reading execution plans. As you learned, execution plans are generated every time you run a query, or at least each query that you run has its own execution plan. It may be cached, it may be generated at run time. But we want to learn how to read those execution plans because they're really key to driving performance in SQL Server and understanding what your code is doing and how it's working. So there are two types of execution plans that exist in SQL Server and that you can see through Management Studio and other related tools. And these are estimated plans and actual plans. And what's the difference between these plans in terms of what we have in terms of data and information? Well, the key thing about an estimated plan is that you can generate an estimated plan without actually running the query. So you don't have to wait for the results to take place. The optimizer will simply compile the query and generate an execution plan. However, the actual…
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Contents
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Execution plans introduction4m 55s
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How to read an execution plan6m 14s
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Execution plan XMLs2m 38s
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Key lookup: When it's good and when it's bad4m 22s
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Nested loop vs. hash join4m 56s
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Query Store7m 54s
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Stored procedures vs. dynamic SQL5m 26s
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Missing index warnings6m 6s
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