DLOG
2003
13 years 6 months ago
2003
This paper presents an application of a DL reasoner to the optimization of an object-relational query language. Queries containing aggregate functions are difficult to optimize be...
DBA
2004
13 years 6 months ago
2004
We argue for a new aggregate function we termed the LIST function. It aggregates a set of values of one or more attributes into a single value that is internally a list of these v...
VLDB
1987
ACM
13 years 8 months ago
1987
ACM
is at least ae powerful as SQL. Two well known relational query languages that have a sound theoretical foundation are relational algebra and relational calculus. As SQL is more cl...
ICDT
1999
ACM
13 years 8 months ago
1999
ACM
Abstract. In this paper we present a new approach for studying aggregations in the context of database query languages. Starting from a broad de nition of aggregate function, we ad...
ICDE
2006
IEEE
14 years 5 months ago
2006
IEEE
A top-k query combines different rankings of the same set of objects and returns the k objects with the highest combined score according to an aggregate function. We bring to ligh...