54 search results - page 1 / 11 » Some properties of the disjunctive languages contained in Q |
ACTA
2011
12 years 11 months ago
2011
ICDT
2007
ACM
13 years 10 months ago
2007
ACM
Query containment is a fundamental problem of databases. Given two queries q1 and q2, it asks whether the set of answers to q1 is included in the set of answers to q2 for any datab...
EJC
2010
13 years 4 months ago
2010
In this paper, we investigate some properties of partial covers of PG(n, q). We show that a set of q + a hyperplanes, q 81, a < (q - 1)/3, or q > 13 and a (q - 10)/4, that...
JUCS
2002
13 years 4 months ago
2002
: We consider disjunctive sequences, that is, infinite sequences (-words) having all finite words as infixes. It is shown that the set of all disjunctive sequences can be described...
CIKM
2009
Springer
13 years 9 months ago
2009
Springer
Tree patterns represent important fragments of XPath. In this paper, we show that some classes of tree patterns exhibit such a property that, given a finite number of tree patter...