189 search results - page 21 / 38 » Translating and Optimizing SQL Queries Having Aggregates |
DKE
2007
13 years 7 months ago
2007
Histogram techniques have been used in many commercial database management systems to estimate a query result size. Recently, it has been shown that they are very effective to su...
PVLDB
2008
13 years 7 months ago
2008
Given a parametrized n-dimensional SQL query template and a choice of query optimizer, a plan diagram is a color-coded pictorial enumeration of the execution plan choices of the o...
SIGMOD
2004
ACM
14 years 7 months ago
2004
ACM
Ranking is an important property that needs to be fully supported by current relational query engines. Recently, several rank-join query operators have been proposed based on rank...
ICDE
2008
IEEE
14 years 9 months ago
2008
IEEE
Abstract-- We present COLR-Tree, an abstraction layer designed to support efficient spatio-temporal queries on live data gathered from a large collection of sensors. We use COLR-Tr...
ICDE
2000
IEEE
14 years 9 months ago
2000
IEEE
In information-integration systems, sources may have diverse and limited query capabilities. In this paper we show that because sources have restrictions on retrieving their infor...