Automatic prunning for log-based replication
AssigneeInternational Business Machines Corporation
InventorsIon Tim Ieong, Patricia Lorraine Shimer
Life of this patent
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Abstract
Automatic pruning of a log used in log-based replication of database tables within a relational database management system. An optimal point at which to prune the log is periodically determined, such that the optimal point provides a minimum amount of storage space for the log and yet ensures that all updates to the database table can be properly replicated from the log. The log is then automatically pruned of selected records prior to the optimal point.
Claims24
A computer-implemented method for automatic pruning of a log used in a log-based replication of at least one database table within a relationable database management system, comprising:
- (a) re-assembling at least one data row of the database table in at least one database structure from the log records;
- (b) marking a first log record for the data row being re-assembled;
- (c) removing the data row from the data structure when it is re-assembled;
- (d) identifying the marked first log record as an optional point at which to prune the log when the data row is removed from the data structure, in order to provide a minimum amount of storage space form the log, and yet ensures that all updates to the data table can be properly replicated from the log;
- and
- (e) automatically pruning the log of selected records prior to the optimal point.
A computer-implemented apparatus for automatic pruning of a log used in a log-based replication of at least one database table within a relational database management system, comprising:
- (a) a computer;
- and
- (b) means, performed by the computer, for re-assembling at least one data row of the database table in at least one database structure from the log records;
- (c) means, performed by the computer, for re-assembling at least one data row being re-assembled;
- (d) means, performed by the computer, for removing the data row from the data structure when it is re-assembled;
- (e) means, performed by the computer, for identifying the marked first log record as an optimal point at which to prune the log when the data row is removed from the data structure, in order to provide a minimum amount of storage space for the log, and yet ensures that all updates to the database table can be properly replicated from the log;
- and
- (f) means, performed by the computer, for automatically pruning the log of selected records.
An article of manufacture embodying logic for automatic pruning of a log used in log-based replication of at least one database table within a relational database management system, comprising:
- (a) re-assembling at least one data row of the database table in at least on data structure from the records;
- (b) marking a first log record for the data row being re-assembled;
- (c) removing the data row from the data structure when it is re-assembled;
- (d) identifying the marked first log record as an optional point at which to prune the log when the data row is removed from the data structure, in order to provide a minimum amount of storage space for the log, and yet assures that all updates to the database table can be properly replicated from the log;
- and
- (e) automatically pruning the log of selected records prior to the optimal point.
Dependencies are inferred from the claim text.