receiving, by at least one computer processor at a middleware system, a request for changes made to a source system from a consumer at a target system, wherein changes to the source system are stored in an enhanced data table in the middleware system, and the middleware system is communicatively coupled to the source system and the target system;

in response to receiving the request, determining a high watermark stored in a consumer registration table based on the consumer, wherein the high watermark is a timestamp calculated according to a clock of the middleware system and is specific to the consumer;

in response to receiving the request, determining a set of open transactions on the enhanced data table, wherein the set of open transactions represent uncommitted changes to the enhanced data table;

determining a set of changes made to the source system that are relevant to the consumer at the target system based on the high watermark and the set of open transactions;

transmitting the set of changes to the consumer at the target system;

receiving a confirmation from the consumer at the target system that the set of changes were committed to the target system; and

updating the high watermark in the consumer registration table based on the confirmation.