Q Replication is a high-volume, low-latency replication solution that uses WebSphere® MQ message queues to transmit transactions between source and target databases or subsystems.

Q Replication captures changes to source tables and converts committed transactional data to messages. The data is not staged in tables. As soon as the data is committed at the source and read by Q Replication, the data is sent to the target location through WebSphere MQ. At the target location, the messages are read from the queues and converted into transactional data. The transactions are then applied to your target tables with a highly parallelized method that preserves the integrity of your data.

You can use Q Replication for a variety of purposes that require replicated data, including failover, capacity relief, geographically distributed applications, and data availability during rolling upgrades or other planned outages. Because of its speed, reliability, and flexibility to replicate in one direction, bidirectionally, or in a peer-to-peer mode that uses timestamps and version columns, Q Replication is a key component in GDPS® Active-Active solutions and can also be used in application migration scenarios.

You can also use Q Replication to replicate data from non-relational tables by using InfoSphere® Classic Replication Server for z/OS, WebSphere MQ, and InfoSphere Replication Server. Classic replication uses its own mechanism for capturing changes. The Classic capture components convert transactions to WebSphere MQ messages that are read by the Q Apply program on InfoSphere Replication Server.

Classic replication sources can be on the non-relational data sources Adabas, CA-IDMS, IMS™, CICS® VSAM files, and VSAM files.

You can replicate a subset of columns and rows from the source tables. All subsetting occurs at the source location so that only the data that you want is transported across the network. If you want to perform data transformations, you can use the SQL column expressions feature in Q Apply or pass replicated data to your own stored procedures.