SQL: Indexes & Query Performance Basics

Find out why some SQL queries take seconds and others take minutes. This course explains what indexes are, how they speed up searches, sorting and joins, what they cost, how to read a basic query plan with EXPLAIN, and simple habits for writing faster, kinder queries.

Tutwoo is an independent learning provider. This course is general skills training based on official documentation. It is not an accredited qualification. Software behaviour can change between versions, so check the official documentation for the version you use.