A method is provided for real-time data processing based on data sets or data sets defined by applicable rules or user-defined logic. Also provided is a real-time data processing system that implements such method. Transaction boundaries are set and propagated through cascades of multiple data transformations on multitudes of data records or rows. The method may be implemented in conjunction with a relational database management system (DBMS), object DBMS, or any other DBMS. The method and system for real-time data processing may be advantageously applied in Extract, Transform, and Load (ETL), Enterprise Application Integration (EAI), and Enterprise Information Integration (EII).