Querying documents in object databases

  • Serge Abiteboul
  • Sophie Cluet
  • Vassilis Christophides
  • Tova Milo
  • Guido Moerkotte
  • Jérôme Siméon
Original articles

structuring schemas

that consist in grammars annotated with database programs. To query documents, we introduce an extension of OQL, the ODMG standard query language for object databases. Our extension (named OQL-doc) allows us to query documents without a precise knowledge of their structure using in particular generalized path expressions and pattern matching. This allows us to introduce in a declarative language (in the style of SQL or OQL), navigational and information retrieval styles of accessing data. Query processing in the context of documents and path expressions leads to challenging implementation issues. We extend an object algebra with new operators to deal with generalized path expressions. We then consider two essential complementary optimization techniques. We show that almost standard database optimization techniques can be used to answer queries without having to load the entire document into the database. We also consider the interaction of full-text indexes (e.g., inverted files) with standard database collection indexes (e.g., B-trees) that provide important speed-up.

Key words: Generalized path expressions ODMG OQL Pattern matching 

Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • Serge Abiteboul
    • 1
  • Sophie Cluet
    • 1
  • Vassilis Christophides
    • 1
  • Tova Milo
    • 2
  • Guido Moerkotte
    • 3
  • Jérôme Siméon
    • 1
  1. 1.INRIA-Rocquencourt, BP 105, F-78153 Le Chesnay Cedex, FranceFR
  2. 2.Tel Aviv University, Ramat Aviv, Tel Aviv 69978, IsraelIL
  3. 3.Lehrstuhl für Praktische Informatik III, Seminargebäude A5, Universität Mannheim, D-68131 Mannheim, GermanyDE

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