708 search results - page 35 / 142 » Optimizing SQL Queries over Text Databases |
PODS
2003
ACM
14 years 7 months ago
2003
ACM
Full disjunctions are an associative extension of the outerjoin operator to an arbitrary number of relations. Their main advantage is the ability to maximally combine data from di...
GIS
2006
ACM
14 years 8 months ago
2006
ACM
Remotely sensed data, in particular satellite imagery, play many important roles in environmental applications and models. In particular applications that study (rapid) changes in...
VLDB
2007
ACM
14 years 7 months ago
2007
ACM
Incompleteness due to missing attribute values (aka "null values") is very common in autonomous web databases, on which user accesses are usually supported through media...
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
2003
IEEE
14 years 9 months ago
2003
IEEE
Query optimizers use base-table statistics to derive statistics on the sub-plans that are enumerated during optimization. In practice, traditional optimizers rely on a number of s...