第7课 系统设计专题 Design Google Doc 課件講到locking 時，有說用partitioned lock to control concurrent access to the same document. e.g. four partitioned lock created in memory at start up. But later, 課件講到 the same document is been editing by more than one users and need to handle the conflict. 這裡是不是有special lock，可以給 多人一起做editing？
I mean, why more than one users can edit the same document at the same time if there are already partitioned locks to control the access?
partitioned locks 对一个document而言没有意义的