Seriously. Like, every junior dev has to learn DB indexing basics sometime, and apparently the other of this blog post just did. But really can’t understand why this article is getting voted to the top of HN.
What I gained from the article wasn't that the dev was unaware of indices, it's that he didn't realise indices were missing due to how planetscale's database disallows foreign keys.
I never worked with a database that doesn't have foreign keys and it's not unthinkable to forget when you do for the first time, that foreign keys were what created indexes for you automatically.
A little bit of planning could have prevented that though :/
