Abstract: Data declaration language (DDL) replication can be performed without stopping the system. In other words, DDL changes can be replicated seamlessly. Within a RDBMS (relational database management system), the execution of a DDL statement involves many internal steps which are not visible to an end user. These steps can be logically divided into three stages, “pre-stage” which refers to the steps before the server makes a physical change to the system catalog for the specific DDL, “middle-stage” which refers to the action of making a change to the system catalog, and “post-stage” which refers to the steps after changes to the system catalog were made. Schema changes are intercepted in both pre-stage and post-stage. Schema changes are intercepted in pre-stage so an old image of schema information can be saved. This helps to support schema versioning logic. Schema changes are intercepted in post-stage so sets of commands can be posted to propagate the schema change, as well as to refresh any dependencies.