Don't Scrap It, Wrap It! A Wrapper Architecture for Legacy Data Sources

Garlic is a middleware system that provides an integrated view of a variety of legacy data sources, without changing how or where data is stored. In this paper, we describe our architecture for wrappers, key components of Garlic that encapsulate data sources and mediate between them and the middleware. Garlic wrappers model legacy data as objects, participate in query planning, and provide standard interfaces for method invocation and query execution. To date, we have built wrappers for 10 data sources. Our experience shows that Garlic wrappers can be written quickly and that our architecture is flexible enough to accommodate data sources with a variety of data models and a broad range of traditional and non-traditional query processing capabilities.

[1]  Laura M. Haas,et al.  Optimizing Queries Across Diverse Data Sources , 1997, VLDB.

[2]  Patrick Valduriez,et al.  Dealing with Discrepancies in Wrapper Functionality , 1997, BDA.

[3]  Calton Pu,et al.  Guest Editors' Introduction to the Special Issue on Heterogeneous Databases , 1990, ACM Computing Surveys.

[4]  Betty Salzberg,et al.  Review - Don't Scrap It, Wrap It! A Wrapper Architecture for Legacy Data Sources , 1999, ACM SIGMOD Digit. Rev..

[5]  Philip Cannata,et al.  SQL Access: an implementation of the ISO Remote Database Access Standard , 1991, Computer.

[6]  Goetz Graefe,et al.  Query evaluation techniques for large databases , 1993, CSUR.

[7]  Ralph L. Stout.  Eda/sql , 1995, Modern Database Systems.

[8]  Joann J. Ordille,et al.  Querying Heterogeneous Information Sources Using Source Descriptions , 1996, VLDB.

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

[10]  Ali R. Hurson,et al.  Object-oriented multidatabase systems , 1995 .

[11]  Won Kim,et al.  Modern Database Systems: The Object Model, Interoperability, and Beyond , 1995, Modern Database Systems.

[12]  Christos Faloutsos,et al.  QBIC project: querying images by content, using color, texture, and shape , 1993, Electronic Imaging.

[13]  Hongjun Lu,et al.  Some Experimental Results on Distributed Join Algorithms in a Local Network , 1985, VLDB.

[14]  José A. Blakeley,et al.  Data access for the masses through OLE DB , 1996, SIGMOD '96.

[15]  Guy M. Lman.  Grammar-like Functional Rules for Representing Query Optimization Alternatives , 1998 .

[16]  Weimin Du,et al.  The Pegasus heterogeneous multidatabase system , 1991, Computer.

[17]  GraefeGoetz.  Query evaluation techniques for large databases , 1993 .

[18]  Ahmed K. Elmagarmid,et al.  Object-Oriented Multidatabase Systems: A Solution for Advanced Applications , 1995 .

[19]  Terry A. Landers,et al.  An Overview of MULTIBASE , 1986, DDB.

[20]  Tom Atwood,et al.  Object Database Standard: ODMG-93, Release 1.2 , 1995 .

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

[22]  Jeffrey D. Ullman,et al.  A Query Translation Scheme for Rapid Implementation of Wrappers , 1995, DOOD.

[23]  Guy M. Lohman,et al.  Optimizer Validation and Performance Evaluation for Distributed Queries , 1998 .

[24]  Laura M. Haas,et al.  Towards heterogeneous multimedia information systems: the Garlic approach , 1995, Proceedings RIDE-DOM'95. Fifth International Workshop on Research Issues in Data Engineering-Distributed Object Management.