53 search results - page 6 / 11 » Preferential Regular Path Queries |
PODS
2004
ACM
14 years 10 months ago
2004
ACM
The problem of deciding query containment has important applications in classical query optimization and heterogeneous database systems. Query containment is undecidable for unres...
ICDE
2002
IEEE
14 years 11 months ago
2002
IEEE
XML and other semi-structured data may have partially specified or missing schema information, motivating the use of a structural summary which can be automatically computed from ...
VLDB
1990
ACM
14 years 1 months ago
1990
ACM
In previous papers we have proposed a graphical query language for expressing traversal recursions in labelled, directed graphs. A fundamental feature of the language is the use o...
NIL
1991
14 years 1 months ago
1991
In this paper we consider supernormal defaults [Poo88] with a strict partial order defining their priorities [Bre91]. We investigate their relation to minimal or preferential ent...
DEXAW
2005
IEEE
13 years 11 months ago
2005
IEEE
In this paper, we study semistructured data and indexes preserving inclusion constraints. A semistructured datum is modelled by multi-rooted edge-labeled directed graphs. We consi...