19 search results - page 2 / 4 » An optimization of disjunctive queries: union-pushdown |
JAR
2007
13 years 5 months ago
2007
As applications of description logics proliferate, efficient reasoning with knowledge bases containing many assertions becomes ever more important. For such cases, we developed a n...
DAWAK
2003
Springer
13 years 11 months ago
2003
Springer
We introduce a new method for optimization of SQL queries with nested subqueries. The method is based on the idea of Boolean aggregates, aggregates that compute the conjunction or ...
SIGIR
2011
ACM
12 years 8 months ago
2011
ACM
Large search engines process thousands of queries per second over billions of documents, making query processing a major performance bottleneck. An important class of optimization...
PODS
2003
ACM
14 years 5 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...
PODS
2010
ACM
13 years 11 months ago
2010
ACM
Both semantic and type-based query optimization rely on the idea that queries often exhibit non-trivial rewritings if the state space of the database is restricted. Despite their ...