A method in a data processing system for propagation of filter expressions
across multi-layered systems. If a selection criteria expression in a
data request received by a first data processing engine from an
application is incompatible with selection criteria expressions of a
second data processing engine, the data request and the portion of the
selection criteria expression that is compatible with selection criteria
expressions of the second data processing engine is transmitted to the
second data processing engine. If the second data processing engine
received a message that matches the compatible portion of the selection
criteria expression, the message that matches is transmitted to the first
data processing engine. If the message that matches the compatible
portion also matches the portion of the selection criteria expression
that is incompatible with the selection criteria expressions of the
second data processing engine, the message that matches is transmitted to
the application.