be.SIRAPRISE.ra

Class AGGREGATE

java.lang.Object

be.SIRAPRISE.ra.RelationalOperator

be.SIRAPRISE.ra.AGGREGATE

public abstract class AGGREGATE
extends RelationalOperator

AGGREGATE

Author:

erwin

Constructor Summary

Constructors

Constructor and Description
AGGREGATE()

Method Summary

Modifier and Type	Method and Description
static Relation	computeAggregate(Relation relation, java.util.Map<NameIdentifier,java.lang.String> expressions)
int	getMaximumArgumentCount() Gets the maximum argument count for this operator.
int	getMinimumArgumentCount() Gets the minimum argument count for this operator.
java.lang.String	getName() Gets the operator name
boolean	isMonoRelationOperator() Checks if the operator takes only one Relation as input

Methods inherited from class be.SIRAPRISE.ra.RelationalOperator

toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AGGREGATE

public AGGREGATE()

Method Detail

computeAggregate

public static Relation computeAggregate(Relation relation,
                                        java.util.Map<NameIdentifier,java.lang.String> expressions)

Parameters:

relation - the relation to be aggregated

expressions - the expressions defining which aggregations to compute, mapped to the attribute names for the respective aggregation results in the relation returned

Returns:

the result of aggregating the given relation according to the given specs

getMaximumArgumentCount

public final int getMaximumArgumentCount()

Description copied from class: RelationalOperator

Gets the maximum argument count for this operator. Note that stuff like rename lists are regarded as an argument as far as this count is concerned

Specified by:

getMaximumArgumentCount in class RelationalOperator

Returns:

the maximum argument count for this operator.

getMinimumArgumentCount

public final int getMinimumArgumentCount()

Description copied from class: RelationalOperator

Gets the minimum argument count for this operator. Note that stuff like rename lists are regarded as an argument as far as this count is concerned

Specified by:

getMinimumArgumentCount in class RelationalOperator

Returns:

the minimum argument count for this operator

getName

public final java.lang.String getName()

Description copied from class: RelationalOperator

Gets the operator name

Specified by:

getName in class RelationalOperator

Returns:

the operator name

isMonoRelationOperator

public final boolean isMonoRelationOperator()

Description copied from class: RelationalOperator

Checks if the operator takes only one Relation as input

Specified by:

isMonoRelationOperator in class RelationalOperator

Returns:

true if the operator takes only one Relation as input