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Fwd: Talk Announcement: Querying Subtree Views

X-Original-To: staff@dbai.tuwien.ac.at
Delivered-To: therese@dbai.tuwien.ac.at
Date: Sun, 17 Oct 2004 17:50:20 +0200 (CEST)
From: Christoph Koch <koch@dbai.tuwien.ac.at>
To: staff@dbai.tuwien.ac.at, staff@kr.tuwien.ac.at,
        scherzinger@wit.tuwien.ac.at, staff@big.tuwien.ac.at, staff@lixto.com
Subject: Talk Announcement: Querying Subtree Views

Date: Thursday, October 21, 2004, 10:30 am s.t.
Place Seminarroom of the Institute, Favoritenstraße 9-11/1842, 3rd floor (when you leave the elevator turn left, go through the corridor, the entrance is on the right side)


Michael Benedikt,
Bell Labs


A frequent task encountered in XML processing is to filter an input
document to produce a subdocument; that is, a document whose
root-to-leaf paths are root-to-leaf paths of the original document and
which inherits the tree structure of the original document.  These are
what we mean by subtree queries, and while they are similar to XPath
filters, they cannot be naturally specified either in XPath or in
XQuery.  Subtree queries can be used in defining views, either in data
integration or in access control, and these views may well be layered
one on top of the other.  We introduce a simple language, XSquirrel,
for specifying subtree queries, parameterized by the nodeset query
language XPath. We then discuss several theoretical and practical
issues in querying XSquirrel views.  For access control views, the
problem is one of query composition; we present algorithms for
composing an XSquirrel or XPath user query with an XSquirrel view, for
several variations of the XSquirrel language.  The next issue is how
to query source data given an XSquirrel view. We present some
preliminary results on querying through subtree views.

The talk includes joint work with Irini Fundulaki, Cristiana Chitic,
and Daniela Rosu