Patent ID: 7065538
Filing Date: 2006-06-20
Classification: G06F,Y10S

Abstract:
1. A device for performing replication between a source system and a target system, the device comprising: a source system having data files, and log files storing replication transactions corresponding to changes made to the data files; a recovered target system wherein the recovered target system comprises a rolled back copy of the data files in the source system and wherein the rolled back copy of the data files comprises data that is associated with at least one replication transaction stored in the log files; and a replication system performing replication of at least portions of the data files of the source system to the recovered target system by reading the log files and posting the changes from the log files to the recovered target system, the replication system comprising: transaction-level poster queues, each poster queue storing statements corresponding to a particular replication transaction from the source system, and a reconcile process which purges replication transactions from the poster queues when the replication transactions have already been applied to the recovered target system; and wherein the replication system performs the replication transactions by rolling forward at least some of the information rolled back during the recovery of the recovered target system such that the purged replication transactions in the poster queues are not applied while rolling forward such that the source database remains available during recovery of the recovered target database.