Interactive program guide with continuous data stream and client-server data supplementation

A system for providing program guide data that includes unique identifiers associated with programs, the system comprising:

• a continuous data stream processor configured to select a particular unique identifier associated with a particular program for inclusion in a continuous data stream;
• distribution equipment configured to distribute the particular unique identifier to user equipment in the continuous data stream when the particular program is currently being broadcasted;
• and
• an interactive program guide implemented on the user equipment configured to:
• monitor the continuous data stream for the presence of the particular unique identifier, wherein the presence of the particular unique identifier indicates when the particular program is being currently broadcasted;
• perform a real-time action associated with the particular program when the particular unique identifier is detected in the continuous data stream;
• and
• prefetch current program guide data from the continuous data stream when the real-time action is performed.