diff --git a/src/db.md b/src/db.md
index 8e426fb..bad233e 100644
--- a/src/db.md
+++ b/src/db.md
@@ -2,6 +2,7 @@
 
 - [ByteScout SQL Trainer](https://app.bytescout.com/sql-trainer/index.html)
 - [Introduction to SQL](https://sqlbolt.com/)
+- [Use the Index, Luke! A Guide to Database Performance for Developers](https://use-the-index-luke.com/)
 - [The Querynomicon](https://gvwilson.github.io/sql-tutorial/)
 - [Things You Should Know About Databases](https://architecturenotes.co/things-you-should-know-about-databases/)
 - [Database Normalization Basics](https://www.lifewire.com/database-normalization-basics-1019735)