DAP Relational Database Server II
In order to provide support for the Sensor Observation Service (SOS) Hyrax will need a handler that allows it to access data in a Relational Database Management System (RDBMS). (This requirement stems from the observation that many of our stake holders store their in situ measurement data in RDBMSs)
In the past a Java servlet called the DODS Relational Database Server (DRDS) was used to provide DAP access to RDBMS holdings. However this older implementation has a number of shortcomings that preclude it's direct use in our current server architecture:
- No longer supported.
- Uses the Java DAP implementation
- Not a BES module
- Significant memory limitations
- Difficult to configure and localize.
Current design is that we not matter the internal structure of the database the operator will create a view (or use existing tables) and the DRDS-1II will query against that view to produce a row set that will be served as a Sequence.
The DDX/DDS/DAS documents will be generated by introspection of the database. We may wish to use a configuration mechanism to identify which table and/or views that are meant to be served, or to instruct the server to serve all of the tables and/or views that it can discover using introspection.
