Key lookups have a bad reputation, but most of them really aren’t that bad – especially when we consider the alternatives, trying to get the developers to select less columns, or building huge covering indexes. However, there’s one kind of key lookup we do need to fix, and it’s easy: the residual predicate.
2.2 Tuning to Avoid Key Lookups and Residual Predicates
Key lookups have a bad reputation, but most of them really aren’t that bad – especially when we consider the alternatives, trying to get the developers to select less columns, or building huge covering indexes. However, there’s one kind of key lookup we do need to fix, and it’s easy: the residual predicate.
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- 0.1 Prerequisites Before the Class (~4 hours)
- 0.2 Download the Slides
- 1.2 The D.E.A.T.H. Method: Dedupe and Eliminate
- 1.3 Why Index Read & Write Numbers Are Wrong
- 1.4 Lab 1 Setup: Dedupe and Eliminate
- 1.4b Lab 1: Dedupe and Eliminate – Brent Does It
- 1.5 The D.E.A.T.H. Method: Tuning Indexes for Specific Queries
- 1.6 Foreign Key and Check Constraints
- 1.7 Lab 2 Setup: Tuning Indexes for Specific Queries
- 1.8 Lab 2: Tuning Indexes for Specific Queries – Brent Does It
- 2.1 Adding Indexes with the DMVs
- 2.3 Lab 3 Setup: Adding Indexes with Clippy and the DMVs
- 2.3b Lab 3: Adding Indexes with Clippy and the DMVs – Brent Does It
- 2.4 The D.E.A.T.H. Method – Heaps and Clustered Indexes
- 2.5 Tuning Indexes to Avoid Blocking
- 2.6 Lab 4 Setup: Solving Blocking with Indexes
- 2.6 Lab 4: Solving Blocking with Indexes – Brent Does It
- 3.1 Filtered Indexes, Indexed Views, and Computed Columns
- 3.2 Lab 5 Setup: Leveraging Artisanal Indexes
- 3.2b Lab 5: Leveraging Artisanal Indexes – Brent Does It
- 3.3 Lab 6 Setup and Final Lessons
- 3.4 Lab 6: Doing the D.E.A.
- 3.5 Lab 6: Doing the D.E.A.T.
- About the Lab Exercises
- Bonus: Storytelling Time
- Bonus: Tips from the Index Sommelier