Ozone: Integrating Structured and Semistructured Data

Applications have an increasing need to manage semistructured data (such as data encoded in XML) along with conventional structured data. We extend the structured object database model ODMG and its query language OQL with the ability to handle semistructured data based on the OEM model and Lorel language, and we implement our extensions in a system called Ozone. In our approach, structured data may contain entry points to semistructured data, and vice-versa. The unified representation and querying of such "hybrid" data is the main contribution of our work. We retain strong typing and access to all properties of structured portions of the data while allowing flexible navigation of semistructured data without requiring full knowledge of structure. Ozone also enhances both ODMG/OQL and OEM/Lorel by virtue of their combination. For instance, Ozone allows OEM semantics to be applied to ODMG data, thus supporting semistructured-style navigation of structured data. Ozone also enables ODMG views of OEM data, allowing standard ODMG applications to access semistructured data without losing the benefits of structure. Ozone is implemented on top of the ODMG-compliant O2 database system, and it fully supports our extensions to the ODMG model and OQL.

[1]  Dan Suciu,et al.  Programming Constructs for Unstructured Data , 1995, DBPL.

[2]  Serge Abiteboul,et al.  Extracting schema from semistructured data , 1998, SIGMOD '98.

[3]  Gio Wiederhold,et al.  Mediators in the architecture of future information systems , 1992, Computer.

[4]  Laks V. S. Lakshmanan,et al.  A declarative language for querying and restructuring the Web , 1996, Proceedings RIDE '96. Sixth International Workshop on Research Issues in Data Engineering.

[5]  Tim Bray,et al.  Presenting Xml , 1997 .

[6]  Guido Moerkotte,et al.  Querying documents in object databases , 1997, International Journal on Digital Libraries.

[7]  Roy Goldman,et al.  Lore: a database management system for semistructured data , 1997, SGMD.

[8]  Nick Roussopoulos,et al.  Interoperability of multiple autonomous databases , 1990, CSUR.

[9]  David Jordan,et al.  The Object Database Standard: ODMG 2.0 , 1997 .

[10]  David Konopnicki,et al.  W3QS: A Query System for the World-Wide Web , 1995, VLDB.

[11]  Alan R. Simon,et al.  Understanding the New SQL: A Complete Guide , 1993 .

[12]  Jennifer Widom,et al.  Object exchange across heterogeneous information sources , 1995, Proceedings of the Eleventh International Conference on Data Engineering.

[13]  R. G. G. Cattell,et al.  The Object Database Standard: ODMG-93 , 1993 .

[14]  Dan Suciu,et al.  A query language for a Web-site management system , 1997, SGMD.

[15]  Serge Abiteboul,et al.  Querying Semi-Structured Data , 1997, Encyclopedia of Database Systems.

[16]  Serge Abiteboul,et al.  Inferring structure in semistructured data , 1997, SGMD.

[17]  Dan Suciu,et al.  Adding Structure to Unstructured Data , 1997, ICDT.

[18]  Dan Suciu,et al.  A query language and optimization techniques for unstructured data , 1996, SIGMOD '96.

[19]  E. F. Codd,et al.  A relational model of data for large shared data banks , 1970, CACM.

[20]  E. F. Codd,et al.  A Relational Model for Large Shared Data Banks , 1970 .

[21]  Dan Suciu,et al.  A Query Language and Processor for a Web-Site Management System , 1997 .

[22]  Alberto O. Mendelzon,et al.  Querying the World Wide Web , 1997, International Journal on Digital Libraries.

[23]  Jennifer Widom,et al.  Query Optimization for XML , 1999, VLDB.

[24]  Jennifer Widom,et al.  The TSIMMIS Project: Integration of Heterogeneous Information Sources , 1994, IPSJ.

[25]  Rick Dobson,et al.  Weaving a better Web , 1998 .

[26]  Peter Buneman,et al.  Semistructured data , 1997, PODS.

[27]  Roy Goldman,et al.  DataGuides: Enabling Query Formulation and Optimization in Semistructured Databases , 1997, VLDB.

[28]  Jennifer Widom,et al.  The Lorel query language for semistructured data , 1997, International Journal on Digital Libraries.

[29]  Michael Stonebraker,et al.  Object-Relational DBMSs: The Next Great Wave , 1995 .

[30]  Jennifer Widom,et al.  Query Optimization for Semistructured Data , 1997 .

[31]  SuciuDan,et al.  A query language and optimization techniques for unstructured data , 1996 .

[32]  François Bancilhon,et al.  Building an Object-Oriented Database System, The Story of O2 , 1992 .