Concurrency-control method and apparatus in a database management system utilizing key-valued locking

摘要

The concurrency-control mechanisms in a database-management system achieves high concurrency by using a lock-mode set larger than that conventionally employed for multi-granularity locking. In a system of key-valued locking in which locks on key-value ranges are acquired separately from the locks on the key values with which they are associated, the IX lock mode conventionally acquired on a range by update, insert, and delete operations is replaced with three separate lock modes respectively associated with those operations and invoked by them for range locking. In key-valued-locking systems in which ranges are locked commonly with the key-values associated with them, the mode set is further expanded so that each mode represents a different combination of range and key-value locks.