342 search results - page 33 / 69 » Conjunctive Queries over Trees |
CSL
2009
Springer
13 years 11 months ago
2009
Springer
We introduce tree-width for first order formulae , fotw(). We show that computing fotw is fixed-parameter tractable with parameter fotw. Moreover, we show that on classes of formul...
DASFAA
2007
IEEE
13 years 11 months ago
2007
IEEE
Abstract. We have defined an XML structural index called the Structure Index Tree (SIT), which eliminates duplicate structures arising from the equivalent subtrees in an XML docume...
ICDT
2010
ACM
14 years 20 days ago
2010
ACM
In XML data exchange, a schema mapping specifies rules for restructuring a source document under the target schema, and queries over the target document must be answered in a way...
SPIRE
2004
Springer
14 years 1 months ago
2004
Springer
Abstract Searching information resources using mobile devices is affected by displays on which only a small fraction of the set of ranked documents can be displayed. In this study ...
SIGMOD
2005
ACM
14 years 8 months ago
2005
ACM
We give semantic characterizations of the expressive power of navigational XPath (also called Core XPath) in terms of first order logic. XPath can be used to specify sets of nodes...