Mongo's ObjectID is defined like this: ObjectId is a 12-byte BSON type, constructed using: a 4-byte value representing the seconds since the Unix epoch, a 3-byte machine identifier, ...
Can I have create an InnoDB table without a PK? If so, would a secondary index be used as the clustered index?
Is it possible to create an InnoDB table without a Primary Key? Since InnoDB tables are structured as clustered index around the PK, what would be the structure of a table without PK? Would that ...