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Dears,
I am working on XML and Heterogeneous Databases, Is there any one who has worked on it or want to share the knowledge. Could anyone please let me know the useful links in this regard.
Regards.
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Good Question:Leads
Hi , 30th Nov 2001 17:36 hrs Mumbai
The best place to look for academic papers is DBLP:
http://dblp.uni-trier.de/
On this system, you can search indexes titles and abstracts. You will need to get the actual papers from somewhere else -- your university library or the authors' Web sites.
More information from an article. For XML related go to More links listed below
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Heterogeneous database interaction occurs at two levels. The first is simply querying different databases. In this case, a join engine using ODBC, OLE DB, or native APIs can simply execute SELECT statements on different databases and then integrate the results. In this case, the join engine performs the same function as the query engine in a database -- optimizing queries, determining what indexes to use, etc. This usually requires a special version of SQL so that the engine knows which database each table is on.
The second is much harder -- attempting to integrate similar data that is stored in different schemas. This might be simple -- for example, one database stores a customer address in the Address column of the Customer table and the other database stores the address in the ADDR column of the CUST table.
Usually, it is much harder. For example, one database might store the address in a single column and the other database might store the address in multiple columns. Other problems are things like one database using a five character field for ZIP code (US postal code) and another databaes using a ten character field for international postal codes. Worse yet, data might be stored in one table in one database and in multiple tables on another database.
In this case, the normal strategy is to define a common schema and write "wrappers" for each database. The wrapper converts the data in each database to the common schema and the data is then processed using this schema. One feature of these types of systems is that the common schema often is non-relational. The reason for this is that each different database often contributes some, but not all, of the data defined in the common schema. The result is that the common schema is "semi-structured" -- that is, it has some structure, but that structure is not as regular as in a relational database. A good place to start with semi structured data is the Lore project at Stanford
(http://www-db.stanford.edu/lore/home/index.html).
=====More Info Links===
http://citeseer.nj.nec.com/chang94interoperable.html
http://citeseer.nj.nec.com/context/139385/0
Interoperable Query Processing among Heterogeneous Databases - Yahui Chang (1994) (Correct
http://www.gca.org/papers/xmleurope2...x/acron_X.html
Cheers
Padmam
Attitude:Attack every problem with enthusiasam ...as if your survival depends upon it
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