Apparatus and method for providing recoverability in mass storage data base systems without audit trail mechanisms
US5138710A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 1990 |
| Grant date | Aug 11, 1992 |
| Priority date | — |
| Expiry date | Apr 25, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2201/80
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Message Segments comprising Messages are stored in a flat file on disk. A unique Message Number is assigned to each Message and each Message Segment is stored at a flat file address (Segment Descriptor) in a record containing the Message Segment data and recovery information. the Recovery Information includes fields for an Available Marker, Message Number, Segment Sequence Number, Final Flag and Last Address. The Available Marker denotes whether the Message Segment is in-use or available. The Message Number field contains the Message Number identifying the Message which contains the Segment. The Segment Sequence Number donotes the order in a Message occupied by the Segment. The Final Flag field contains a flag if the Messge Segment is the Last Segment of the Message. The Last Address field contains the Segment Descriptor of the Last Message Segment of the Message containing the Segment. A data base for accessing the Message Segments is maintained on disk. Each data base record contains the Message Number identifying the Message and the Segment Descriptors of the Message Segments comprising the Message. Recovery and rebuilding of the data base from the Recovery Information in the fl…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.