Cache memory with data compaction for use in the audit trail of a data processing system having record locking capabilities
US5193162A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1989 |
| Grant date | Mar 9, 1993 |
| Priority date | — |
| Expiry date | Nov 6, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99953
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A multiprocessor data processing system is implemented with processors, each of which may request for a temporary time the exclusive lock on an object which is stored on a data base. To achieve this a lock processor synchronizes the locking and unlocking of the objects. The requesting processor directs the storage of the object from the data base into a selected high performance storage unit, where it has exclusive rights to modify or write into the object until the object is unlocked by the processor. An audit tape or disk records all modifications made to any object during a transaction. A non-volatile cache memory is inserted in the audit trail to store a before-look image of the object that resides in the high performance storage unit. Data compaction occurs by comparison of the before-look image with an after-look image to provide a difference image, which is supplied to an audit buffer that is coupled to the audit tape. The locking processor may unlock the secured object once the after-look image has been committed from either a stored version in the non-volatile cache or from a high performance main memory unit to the data base disk. The difference image and the after-look i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.