Locking Primitives in a Database System
Henry F. Korth · Journal of the ACM · 1983
Locking ~s a frequently used concurrency control mechamsm m database systems.Most systems offer one or more lock modes, usually read and write modes.Here, one operatwnal lock mode is assumed for each database operation, and a criterion for "good" lock compatibdlty functions, called maximal permtssiveness, is gtven Operatmnal modes are used as a basis to define generalized update modes that correspond to arbitrary lock conversions.The notion of intention modes from System R is extended to arbnrary lock modes, and the mteractmn among the classes of lock modes thus created is studied.