How to use EXPLAIN in PostgreSQL?

Question

PostgreSQL

Here I have a rather long query plan in front of me.
How to read it? What takes a long time and what doesn't? Which indexes to create, and which ones are superfluous?

Answer 1

Next to each step of the query plan is the approximate cost of the step.
If you do EXPLAIN ANALYZE, the real cost of the step will also be indicated.
Show me the plan? In a nutshell, it is impossible to teach how to read plans without an example.
Yes, superfluous indexes are visible not in plans. They can be seen in the index usage statistics.