88 search results - page 2 / 18 » Exploiting statistics on query expressions for optimization |
SIGMOD
2007
ACM
14 years 5 months ago
2007
ACM
Good cardinality estimates are critical for generating good execution plans during query optimization. Complex predicates, correlations between columns, and user-defined functions...
ADBIS
2005
Springer
13 years 11 months ago
2005
Springer
XQuery is widely used for querying XML documents. Within this paper, we examine optimization rules for XQuery queries that exploit type information of the input XML document given ...
SIGMOD
2007
ACM
14 years 5 months ago
2007
ACM
Complex queries often contain common or similar subexpressions, either within a single query or among multiple queries submitted as a batch. If so, query execution time can be imp...
PVLDB
2010
13 years 3 months ago
2010
Optimization of join queries based on average selectivities is suboptimal in highly correlated databases. In such databases, relations are naturally divided into partitions, each ...
ICDE
2012
IEEE
11 years 7 months ago
2012
IEEE
—Many companies now routinely run massive data analysis jobs – expressed in some scripting language – on large clusters of low-end servers. Many analysis scripts are complex ...