From OPeNDAP Documentation
⧼opendap2-jumptonavigation⧽
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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)
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| It is anticipated RDBMS handler will have a much broader application than just SOS related data sets.
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| == Use Cases ==
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| # [[Add the DRDS-II handler to the BES]]
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| # [[Configure DRDS-II to use ODBC introspection to build catalog of database holdings]]
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| # [[Configure DRDS-II to use a local configuration to build catalog of database holdings]]
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| == Definitions ==
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| ; row set
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| : A ''row set'' is an object which encapsulates a set of [http://en.wikipedia.org/wiki/Row_(database) 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''.
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| == Background ==
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| 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:
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| * No longer supported.
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| * Uses the Java DAP implementation
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| * Not a BES module
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| * Significant memory limitations
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| * Difficult to configure/localize
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| == Design ==
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| 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.
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| === Data model ===
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| 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.
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| == Deliverables ==
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| == Period of use ==
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Latest revision as of 22:45, 27 April 2009