Replicating deletion information using sets of deleted record IDs
First Claim
1. A method of reducing storage requirements when replicating information regarding deleted records in a distributed network of replicas, wherein records in the replicas have unique record identification numbers, the method comprising the steps of:
- storing at a first replica a first set of deleted record identification (DRID) numbers that identify records deleted from the first replica, the first set of DRID numbers being stored without associated change numbers;
modifying the first set of DRID numbers by adding new record identification numbers to the first set of DRID numbers to identify additional records, without associated change numbers, for newly deleted records from the first replica; and
replicating information regarding deleted records to other replicas by sending to said other replicas information corresponding to the modified first set of DRID numbers stored in the first replica in order to thereby reduce storage requirements for representing deleted records.
2 Assignments
0 Petitions
Accused Products
Abstract
Deleted database records are identified not by the use of tombstones (pairs of record IDs and change numbers) but by storing for each database replica a set of deleted record IDs without associated change numbers (DRID data). The DRID data can include not only IDs of deleted records but also IDs that were never assigned to the database by the server (e.g., IDs assigned to records of other databases). The DRID data can be compactly stored as a list of intervals, with each interval describing a range of IDs across which records have either been deleted or never assigned to the database. Replication is accomplished by periodically sending the DRID data, or incremental versions thereof, to other replicas, which delete records identified by the received DRID data, and update their existing DRID data by combining it with received DRID data.
40 Citations
14 Claims
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1. A method of reducing storage requirements when replicating information regarding deleted records in a distributed network of replicas, wherein records in the replicas have unique record identification numbers, the method comprising the steps of:
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storing at a first replica a first set of deleted record identification (DRID) numbers that identify records deleted from the first replica, the first set of DRID numbers being stored without associated change numbers; modifying the first set of DRID numbers by adding new record identification numbers to the first set of DRID numbers to identify additional records, without associated change numbers, for newly deleted records from the first replica; and replicating information regarding deleted records to other replicas by sending to said other replicas information corresponding to the modified first set of DRID numbers stored in the first replica in order to thereby reduce storage requirements for representing deleted records. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A computer program product for use in a computer system that employs a method for replicating information regarding deleted records in a distributed network of replicas, wherein records in the replicas have unique record identification numbers, the computer program product comprising:
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a computer-readable medium for carrying computer program code means used for operating said computer system to employ said method for replicating information regarding deleted records, and computer program code means comprising; program code means for storing at a first replica a first set of deleted record identification (DRID) numbers that identify records deleted from the first replica, the first set of DRID numbers being stored without associated change numbers; program code means for modifying the first set of DRID numbers by adding new record identification numbers to the first set of DRID numbers to identify additional records, without associated change numbers, for newly deleted records from the first replica; and program code means for replicating information regarding deleted records to other replicas by sending to said other replicas information corresponding to the modified first set of DRID numbers stored in the first replica in order to thereby reduce storage requirements for representing deleted records. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification