org.openrdf.query.algebra
Class Avg

java.lang.Object
  org.openrdf.query.algebra.QueryModelNodeBase
      org.openrdf.query.algebra.UnaryValueOperator
          org.openrdf.query.algebra.AggregateOperatorBase
              org.openrdf.query.algebra.Avg

All Implemented Interfaces:

Cloneable, AggregateOperator, QueryModelNode, ValueExpr

public class Avg
extends AggregateOperatorBase

The AVG operator as defined in http://www.w3.org/TR/sparql11-query/#aggregates.

Note that we introduce AVG as a first-class object into the algebra, despite it being defined as a compound of other operators (namely, SUM and COUNT). This allows us to more easily optimize evaluation.

Author:

Jeen Broekstra

Field Summary

Fields inherited from class org.openrdf.query.algebra.UnaryValueOperator

arg

Constructor Summary

Avg(ValueExpr arg)

Avg(ValueExpr arg, boolean distinct)

Method Summary

Avg	clone() Returns a (deep) clone of this query model node.
boolean	equals(Object other) Returns true if this query model node and its children are recursively equal to o and its children.
int	hashCode()
<X extends Exception> void	visit(QueryModelVisitor<X> visitor) Visits this node.

Methods inherited from class org.openrdf.query.algebra.AggregateOperatorBase

isDistinct, setDistinct

Methods inherited from class org.openrdf.query.algebra.UnaryValueOperator

getArg, replaceChildNode, setArg, visitChildren

Methods inherited from class org.openrdf.query.algebra.QueryModelNodeBase

getParentNode, getSignature, nullEquals, replaceNodeInList, replaceWith, setParentNode, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.openrdf.query.algebra.QueryModelNode

getParentNode, getSignature, replaceChildNode, replaceWith, setParentNode, toString, visitChildren

Constructor Detail

Avg

public Avg(ValueExpr arg)

Avg

public Avg(ValueExpr arg,
           boolean distinct)

Method Detail

visit

public <X extends Exception> void visit(QueryModelVisitor<X> visitor)
           throws X extends Exception

Description copied from interface: QueryModelNode

Visits this node. The node reports itself to the visitor with the proper runtime type.

Throws:

X extends Exception

equals

public boolean equals(Object other)

Description copied from interface: QueryModelNode

Returns true if this query model node and its children are recursively equal to o and its children.

Specified by:

equals in interface QueryModelNode

Overrides:

equals in class UnaryValueOperator

hashCode

public int hashCode()

Overrides:

hashCode in class UnaryValueOperator

clone

public Avg clone()

Description copied from interface: QueryModelNode

Returns a (deep) clone of this query model node. This method recursively clones the entire node tree, starting from this nodes.

Specified by:

clone in interface AggregateOperator

Specified by:

clone in interface QueryModelNode

Specified by:

clone in interface ValueExpr

Overrides:

clone in class AggregateOperatorBase

Returns:

A deep clone of this query model node.