Accession Number : ADD018093

Title :   Replay Recovery Protocol for Real-Time Database Management Systems.

Descriptive Note : Patent, Filed 28 Apr 94, patented 4 Jun 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Fortier, Paul J

Report Date : 04 Jun 1996

Pagination or Media Count : 12

Abstract : A computer database method using data organized data into atomic data sets and transactions separated into a plurality of statements called projections which operate on only one said atomic data set. Statements such as read commands, write commands, assignment commands, transaction delimiting commands, and projection delimiting commands are executed, and a depends on graph is created during execution of the statements. Projection recovery data is stored during operation. When a projection requests commit the depends on graph is analyzed to determine if the projection is depends on another projection in the transaction. The projection is committed if it is independent or delayed until commit of the projection on which it depends. Unlike, the system determines projections dependent on the aborting projection and aborts the projections together if a transaction error occurs. A replay method is presented for restarting aborted projections.

Descriptors :   *DATA BASES, *DATA MANAGEMENT, *REAL TIME, *PATENTS, RECOVERY, EXPERIMENTAL DATA, COMPUTERS, GRAPHS, ATOMIC PROPERTIES

Subject Categories : Computer Systems

Distribution Statement : APPROVED FOR PUBLIC RELEASE