High speed system and method for replicating a large database at a remote location

A computer program product for use in conjunction with a backup computer system so as to replicate database updates performed on a primary system, the computer program product comprising a computer readable storage medium and a computer program mechanism embedded therein, the computer program mechanism comprising:

• a Receiver Module for processing a stream of audit records received from the primary system, the audit records including audit update records and audit backout records indicating database updates and database backouts generated by transactions executing on the primary system, and for storing the audit update records and audit backout records in one or more image trails;
• at least one Updater Module that sequentially applies to a backup database the database updates and backouts indicated by the audit update records and audit backout records in the image trails, in the order the audit update records and audit backout records are stored in the image trails and without regard to whether corresponding transactions in the primary system committed or aborted;
• and
• an Undo List Generation Module that, upon the occurrence of a predefined event, generates and Undo List of primary system transactions for which a commit/abort outcome is unknown;
• wherein the at least one Updater Module includes instructions, responsive to the occurrence of the predefined event and the generation of the Undo List, for undoing database updates previously applied to the backup database for the transactions listed in the Undo List.

A backup computer system for replicating database updates performed on a primary system, comprising:

• a backup database;
• a Receiver Module for processing a stream of audit records received from the primary system, the audit records including audit update records and audit backout records indicating database updates and database backouts generated by transactions executing on the primary system, and for storing the audit update records and audit backout records in one or more image trails;
• at least one Updater Module that sequentially applies to a backup database the database updates and backouts indicated by the audit update records and audit backout records in the image trails, in the order the audit update records and audit backout records are stored in the image trails and without regard to whether corresponding transactions in the primary system committed or aborted;
• and
• an Undo List Generation Module that, upon the occurrence of a predefined event, generates and Undo List of primary system transactions for which a commit/abort outcome is unknown;
• wherein the at least one Updater Module includes instructions, responsive to the occurrence of the predefined event and the generation of the Undo List, for undoing database updates previously applied to the backup database for the transactions listed in the Undo List.