Indexes in MongoDB?

Question

MongoDB

Good afternoon!
I would like to ask.
For example, there is a collection = {name, age}
I create indexes
db.users.createIndex( { name: 1, age: -1 } )
When I start the application, db.users.createIndex( { name: 1, age: -1 }) is always executed ) (Well, logically)
Does this affect performance?
Maybe I need to first create indexes through mongo in the terminal?

Answer 1

If you call multiple createIndex() methods with the same index specification at the same time, only the first operation will succeed, all other operations will have no effect.

https://docs.mongodb.com/manual/reference/method/d... Does
n't affect anything at all.