25 search results - page 1 / 5 » Size and treewidth bounds for conjunctive queries |
PODS
2009
ACM
14 years 2 days ago
2009
ACM
PODS
2008
ACM
14 years 5 months ago
2008
ACM
Conjunctive query (CQ) evaluation on relational databases is NP-complete in general. Several restrictions, like bounded tree-width and bounded hypertree-width, allow polynomial ti...
ICDT
2001
ACM
13 years 9 months ago
2001
ACM
A number of efficient methods for evaluating first-order and monadic-second order queries on finite relational structures are based on tree-decompositions of structures or quer...
PODS
2004
ACM
14 years 5 months ago
2004
ACM
Unions of conjunctive queries, also known as select-project-join-union queries, are the most frequently asked queries in relational database systems. These queries are definable b...
ICDT
2012
ACM
11 years 7 months ago
2012
ACM
We introduce a representation system for relational data based on algebraic factorisation using distributivity of product over union and commutativity of product and union. We giv...