Is it worth getting rid of JOIN by adding a new SELECT to SQL?

Question

MySQL

There is a main table with ID of some objects from another table. We need to get the names of these objects.
They often write that JOINs slow down, they must be removed for optimization. So, in this case, is it better to get the names of objects by a separate SELECT or not?

Answer 1

Часто пишут что JOIN-ы тормозят, их надо убирать для оптимизации.

Lies.

Answer 2

EXPLAIN to help you. And so as not to slow down - a competent orchanization of the database and indexes.

Answer 3

I had cases in my work when removing joins speeded up queries.
But this only came to light after hours of working with Explain. in 99% of cases - join is faster.
learn how to use explain.

Answer 4

Do this and that and compare the results