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If you are looking to master SQL queries, understand the nuts and bolts of databases, and achieve optimum time efficiencies, then you’ve come to the right place. In this blog post, we will discuss the best courses that will move you from SQL novice to a proficient query writer, along with some critical examples of SQL code.
The Basics of Query Optimization
Before delving into the best courses, let’s quickly brush up on the concept of query optimization. In simple terms, query optimization is about how to use the SQL language effectively so that the data server can process requests more quickly. A well-optimized query means lower response times and reduced database workload.
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-- Query without optimization SELECT * FROM Employees WHERE Department = 'Sales'; |
The above piece of code selects everything from the Employees table where the department is ‘Sales’. However, if your database houses thousands of employees, the server will take more time to process this request.
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-- Query with optimization (using indexed columns) SELECT ID, First_name, Last_name FROM Employees WHERE Department = 'Sales'; |
In the optimized query, rather than asking the server to fetch every column, we are specifying only the columns needed. This reduces processing time and server load.
Best Courses for SQL Query Optimization
1. Learning SQL by Alan Beaulieu
This book-course is an excellent introduction to SQL. It thoroughly covers all the topics, including query optimization. Fill-in-the-blanks style exercises after every chapter give hands-on experience and strengthen learning.
2. SQL Performance Explained by Markus Winand
A must-read for every developer, this book focuses on tuning SQL performance and contains examples compatible with almost all SQL databases.
3. SQLBolt
SQLBolt provides a more interactive learning experience with immediate feedback. It includes lessons on all SQL topics, and it also has exercises that help solidify the knowledge gained.
Conclusion
So, don’t wait anymore. Delve into these courses, practice SQL queries, and keep optimizing your queries for the best results. Remember, “Practice does not make perfect. Only perfect practice makes perfect” – Vince Lombardi.
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-- Practice Perfectly SELECT ID, First_name, Last_name FROM Employees WHERE Department = 'Sales' AND Year_hired > 2015; |
Happy learning!