710 search results - page 14 / 142 » Relational Expressive Power of Constraint Query Languages |
DBPL
1999
Springer
13 years 12 months ago
1999
Springer
We consider IES(SQL), the incremental evaluation system over an SQL-like language with grouping, arithmetics, and aggregation. We show that every second order query is in IES(SQL) ...
LOGCOM
2007
13 years 7 months ago
2007
We consider the problem of incorporating arbitrary preferences in planning systems. A preference may be seen as a goal or constraint that is desirable, but not necessary, to satis...
ICDT
1997
ACM
13 years 11 months ago
1997
ACM
Abstract. The goal of this paper is to study tractable iteration mechanisms for bags. The presence of duplicates in bags prevents iteration mechanisms developed in the context of s...
ICDT
2003
ACM
14 years 26 days ago
2003
ACM
We study extensions of first-order logic over the reals with different types of transitive-closure operators as query languages for constraint databases that can be described by...
SOFSEM
2004
Springer
14 years 1 months ago
2004
Springer
Abstract. Research on processing XML documents gained much activity in recent times. XML query languages are mostly based on XPath expressions, which are used to select parts of XM...