ITS (Intelligent Transport Systems) services that communicate with a database like AHS (Advanced Cruise-Assist Highway System) often require that many client programs access the same database simultaneously. Moreover, results are required immediately when clients ask for data periodically. An AHS model system was developed that measured communication processing time and database-processing time, as well as performance when many clients access the same server simultaneously in order to clarify the predominant factors that determine the time performance of the database communication function. It was found that time performance was given by three factors. The three factors are the quantity of data stored in the database, whether the database system is distributed or centralised, and the number of simultaneous accesses. This knowledge can be applied to control the performance of developing systems. For the covering abstract see ITRD E114174.
Samenvatting