[prpl]

This is good advice but sometimes you will need to nest things depending on database and optimizer and how it handles CTEs, especially if you ever mess with recursive things. An additional problem here is that there’s no standard way to represent EXPLAIN queries across systems so that makes an additional barrier to entry unfortunately.

[tpetry]

> An additional problem here is that there’s no standard way to represent EXPLAIN queries across systems so that makes an additional barrier to entry unfortunately.

What so you mean by this?

[prpl]

The outputs from each DBMS are often specific to their implementation, even when there is a lot of overlap. The good news is they are usually similar enough and user friendly enough that an advanced user will have no issue but for beginners it can be daunting.

[fomine3]

Anyway beginners learn by just using single RDBMS, isn't it?

[prpl]

Not necessarily. I often see people learn starting with SQLite because it's easy/installed (and quite a bit of tutorials start with it, especially for Python), and then move to MySQL/Postgres, but that is N=2 so it's not too bad.