Performance question with indexes

[masudhossain]

I saw the author wrote Hint: You should add a database index on messages.created_at., which I've tried but performance is still very very slow right now.

Maybe i'm misunderstanding it. I'm suppose to add :created_at index to the messages database table, right?

Example: add_index(:messages, :created_at)

[fatkodima]

I'm suppose to add :created_at index to the messages database table, right?

Yes.

Can you share an explain analyze of your slow query?