Best Practices

Indexes

2 Indexes vs. Combined Index

In most cases a combined index is better than 2 indexes.

Joins

Field-Type

Do not use varchar() or char() aka string types of join field
better: integer (unsigned) && same size
- e.g. actor_id id int unsigned

Views

General

Only use views with merge
NO temptable please, these CANNOT be indexed.

Where

No functions in where please

Why ? Index cannot be used.
example:
- select first_name from actor where upper(first_name) like 'A%'

Alternative solution

use a virtual field and index virtual field (possible from mysql > 5.7)
Massive improvements in mysqL 8