Patent ID: 8121978

Claim:
A method for capturing database changes at a primary database and applying those changes to a replicate database while the replicate database remains on-line and available for use, the method comprising: monitoring transactions occurring at the primary database for detecting changes made to the primary database; recording information about transactions observed to have occurred at the primary database in a transaction log; synchronously copying the information about the transactions recorded in the transaction log to a remote site, so as to create at the remote site a mirrored transaction log that is guaranteed to contain at a synchronized point in time an exact copy of the transactions recorded in the transaction log at the primary database; copying database schema from the primary database to the remote site when the database schema is determined to be modified, to enable transactions to be reconstructed and applied at the replicate database; wherein said monitoring and recording steps occur at a primary site; wherein, while the replicate database remains on-line and available for use, changes made at the primary database are replicated to the replicate database by: said transactions at the replicate database being reconstructed based on the information about the transactions copied to the mirrored transaction log, the information including database schema of the primary database identified as modified and copied to the remote site; and the reconstructed transactions being asynchronously applied at the replicate database; wherein the primary site and remote site are different physical locations.