Response times depend largely on the type of system you have and the system load at the time, although the number of database accesses needed to process your query also plays a part. The actual processing of the data has virtually no effect on the runtime.
Reducing Database Accesses
The InfoSet you choose (see Creating and Changing Queries) determines the database to be evaluated. Each database has an associated selection screen which is automatically displayed when you start a query. Any selections you enter on this screen directly affect the response time. The more precisely you select your data, the shorter the response time will be.
Also make use of the dynamic selections facility. Dynamic selections also directly affect response times.