Indexes
An index is the book’s table of contents. Use it.
▶ the lesson · ~35s · narrated · tap for sound
the intro
An index is a sorted lookup structure that lets the database find rows without scanning the whole table. Queries on indexed columns go from seconds to milliseconds. The trade: indexes make reads fast and writes slightly slower, so index what you query, not everything.
fun fact ✦
A missing index on one column can be the difference between 4ms and 4 seconds. Same query, same data.
the docs
quick hits about Indexes
15-second answers · interviews, tips, trivia & hidden gems
🎤 interview
What is an index?
📚 tutorial
When does an index hurt?
🔧 useful
Column order matters
💎 deep
Index only the rows you query
💎 deep
Read EXPLAIN like a pro