I have a question about the _id field in MongoDB.
Application P, currently developed with Spring Boot, will insert documents into Mongo DB while running multiple instances.
But the point at which the document is stored in MongoDB is very important. So, in application P, I'm going to leave the _id field of the document blank and insert it so that an ObjectId is created automatically, and then I'm going to use the ObjectId's timestamp.
I have a question for you here. When saving a document in Mongo DB, if the _id field is empty and the save is attempted, is the _id field initialized in application P or automatically initialized in Mongo DB?