http://use-the-index-luke.com/3-minute-test

The 3-Minute Test: What do you know about SQL performance?

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“SQL-Tuning is black magic like alchemy:it consists of obscure rules,understood only by a handfulof insiders.”

That is a myth. SQL databases use well-known algorithms to deliver predictable performance. It is, however, easy to write SQL queries that cannot use the most efficient algorithm and thus deliver unexpected performance.

The following questions provide examples that might make you believe that SQL tuning is black magic. The explanations at the end are just a few sentences long and reveal that the black magic is pure science.

Choose your Database

MySQLOracle PostgreSQL SQL Server  

About the Author

Markus Winand tunes developers for high SQL performance. He also published the bookSQL Performance Explained and offers in-house training as well as remote coaching at http://winand.at/

The 3-Minute Test

Expert, competent, or just a greenhorn? Test your SQL performance skills in just three minutes. ›

Table of Contents

• Preface
• Anatomy of an Index
• The Where Clause
• Performance and Scalability
• The Join Operation
• Clustering Data
• Sorting and Grouping
• Partial Results
• Insert, Delete and Update
• Execution Plans
• Myth Directory
• Glossary
• Example Schema

Latest Blog Posts

• Modern SQL in PostgreSQL [and other databases]
• Seven Surprising Findings About DB2
• Meta-Post: New Mascot, New Language, New Database
• We need tool support for keyset pagination
• Finding All the Red M&Ms: A Story of Indexes and Full‑Table Scans
• What I learned about SQLite…at a PostgreSQL conference
• What’s left of NoSQL?
• Thank You MySQL, We’ll Miss You!
• Results of the SQL Performance Quiz: 60% fail
• Unreasonable Defaults: Primary Key as Clustering Key

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