DAP Relational Database Server II: Difference between revisions

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In order to provide support for a [http://www.opengeospatial.org/standards/sos Sensor Observation Service (SOS)] implementation 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)


It is anticipated RDBMS handler will have a much broader application than just SOS related data sets.
== Use Cases ==
# [[Add the DRDS-II handler to the BES]]
# [[Configure DRDS-II to use ODBC introspection to build catalog of database holdings]]
# [[Configure DRDS-II to use a local configuration to build catalog of database holdings]]
== Definitions ==
; row set
: A ''row set'' is an object which encapsulates a set of rows. [http://en.wikipedia.org/wiki/Database_table Database tables] are ''row sets''.  A database ''[http://en.wikipedia.org/wiki/View_(database) view]'' is a ''row set''. [http://en.wikipedia.org/wiki/SQL_query SQL queries] return ''row sets''. [http://en.wikipedia.org/wiki/Join_(SQL) SQL JOIN] operations take ''row sets'' as input and produce ''row sets''.
== Background ==
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/localize
== Design ==
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.
== Deliverables ==
== Period of use ==

Latest revision as of 22:45, 27 April 2009