Patent ID: 7603389

Claim:
A method of processing statement text and statement data of a transaction in a process for replicating I/O operations of the transaction from a source database to a target database in a data replication system that includes (i) a change queue, and (ii) a replication engine for use in replicating the I/O operations from the source database to the target database, wherein a statement cache caches statement text associated with I/O operations to be replicated and a first memory location persistently stores statement text associated with I/O operations to be replicated, the method comprising: (a) caching I/O operations of the transaction to be replicated in the statement cache by separating the I/O operations into: (i) statement text, and (ii) statement data; (b) determining if the statement text has been previously stored in the first memory location; (c) the data replication system replicating the statement text only if it is determined that the statement text is not previously stored in the first memory location, the data replication system thereby avoiding the need to re-replicate the statement text if the statement text has been previously stored in the first memory location; (d) persistently storing the statement text associated with the replicated I/O operations in the first memory location whenever the statement text is replicated; (e) storing the statement data and statement text in a change queue associated with the source database, wherein the I/O operations to be replicated are obtained from the change queue associated with the source database; and (f) the replication engine obtaining I/O operations from the change queue associated with the source database.