26 search results - page 5 / 6 » Improved Unnesting Algorithms for Join Aggregate SQL Queries |
ICDE
2007
IEEE
14 years 7 months ago
2007
IEEE
Algorithms that exploit sort orders are widely used to implement joins, grouping, duplicate elimination and other set operations. Query optimizers traditionally deal with sort ord...
IDEAS
2000
IEEE
13 years 10 months ago
2000
IEEE
Most operations of the relational algebra or SQL - like projection with duplicate elimination, join, ordering, group by and aggregations - are efficiently processed using a sorted...
VLDB
1990
ACM
13 years 9 months ago
1990
ACM
In this paper, we describe a new indexing technique, the time indez, for improving the performance of certain classes of temporal queries. The time index can be used to retrieve v...
SIGMOD
2007
ACM
14 years 6 months ago
2007
ACM
A lot of research has been conducted by the database community on methods and techniques for efficient XPath processing, with great success. Despite the progress made, significant...
ICDE
2008
IEEE
14 years 7 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...