public interface CardinalityEstimator
Interface for any component that estimates the number of results expected when executing a given expression.
Modifier and Type | Method and Description |
---|---|
long |
getCardinality(org.openrdf.query.algebra.TupleExpr expr)
This method estimates the cardinality of the results of executing
expr without making reference to a specific data source. |
long |
getCardinality(org.openrdf.query.algebra.TupleExpr expr,
org.openrdf.model.URI source)
This method estimates the cardinality of the results of executing
expr at data source source . |
long getCardinality(org.openrdf.query.algebra.TupleExpr expr)
expr
without making reference to a specific data source.
This method call is not valid for all types of expressions,
as some expressions can only be estimated in reference to a
specific data source.expr
- long getCardinality(org.openrdf.query.algebra.TupleExpr expr, org.openrdf.model.URI source)
expr
at data source source
.expr
- source
- Copyright © 2015 SemaGrow - FP7. All rights reserved.