The inverted page table includes a transaction locking mechanism . Page protection bits may instead be used when transaction locking is not required. A CPR transaction is all the storage actions by a process on a set of file segments, performed between two calls to commit for that set of segments, including actions of the supervisor in directory segments when files are created, renamed, etc. File open options influence transaction processing. When open options specify file sharing and implicit functions of serialization and atomic commit, we call the file segments database storage .
Transaction locking hardware is used.
Lock fault interrupts invoke the storage manager to grant locks and later, when a transaction commits, the storage manager writes log records of changed storage. Strong transaction properties are achieved, without explicit calls from programs which access storage and independently of superimposed data organization or access pattern. A language-based approach to invoking transaction functions seems to be more explicit and restrictive. Computation with large aggregates over multiple file segments is possible, exceeding 32-bit addressing. Database storage is a new way to implement certain storage management functions in an operating system, built on and similar in spirit to virtual storage.