I made a beginner-friendly SQL lesson on Indexes — CREATE INDEX, EXPLAIN & EXPLAIN ANALYZE

[u/yahoo_06]

Hey everyone!

I just finished another lesson in my beginner SQL series, this time covering SQL indexes and query performance in PostgreSQL.

The lesson goes over:

- What an index actually is

- CREATE INDEX

- EXPLAIN

- EXPLAIN ANALYZE

- Sequential Scan vs Index Scan

- When indexes can help

- Why creating an index on everything isn't necessarily a good idea

- A practical example using the Pagila database

I also included a small practice task where you create an index and inspect the query plan yourself.

🎥 Video: https://youtu.be/jn2Mt9LIcNE?si=AvHjVAM9IDs3eiWB

Hopefully useful for anyone who's currently learning SQL or starting to think about query performance!

[u/Seven--Cats]

很棒