Even if it were simple to store and retrieve output of the hydrodynamics model, a single step from the chemical transport simulation needs to average the output from several steps of the hydrodynamics simulation. A standard database can only store and retrieve individual hydrodynamic snapshots. A more efficient approach would let the database average the snapshots and perform other basic processing. The assumption is that the processing will be too application-specific to warrant common support. The ADR project, led by Saltz, integrates data retrieval with processing, because many scientific applications have similar processing requirements, at least for formatting data returned from a database.
Integrated processing has three main advantages.
Second, by overlapping processing and retrieval, ADR can mask query latencies and improve efficiency. Without parallelism, operations can take up to twice as long. Finally, ADR minimizes the amount of data transmitted from server to client because the processed data is often much smaller than the amount of data accessed. The processing operations can't depend on the order data is retrieved. The ADR can be customized for various applications, while the system provides a uniform interface to the data and processing.