be.SIRAPRISE.ra

Class GROUP

java.lang.Object

be.SIRAPRISE.ra.RelationalOperator

be.SIRAPRISE.ra.GROUP

public abstract class GROUP
extends RelationalOperator

Author:

erwin

Constructor Summary

Constructors

Constructor and Description
GROUP()

Method Summary

Modifier and Type	Method and Description
static RelationBuffer	computeGroup(RelationBuffer relationBuffer, java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes, java.util.Set<NameIdentifier> retainedAttributeNames)
static Relation	computeGroup(Relation relation, java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes)
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
static GROUPInvocationResultDetails	validateExpressionDetails(Heading heading, java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes, java.lang.String predicate, java.util.Collection<? extends KeyDef> inputKeySpecifications)

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

GROUP

public GROUP()

Method Detail

computeGroup

public static Relation computeGroup(Relation relation,
                                    java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes)
                             throws EvaluationException

Parameters:

relation - the relation to be subjected to grouping

groupAttributes - The specification of the groupings to be applied. Each entry consists of an attribute name for the relation-valued attribute in the result, and the set of attributes of this relation that that relation-typed attribute is to include.

Returns:

the given relation, grouped together according to the specs provided in groupAttributes

Throws:

EvaluationException - If the evaluation fails for any reason

computeGroup

public static RelationBuffer computeGroup(RelationBuffer relationBuffer,
                                          java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes,
                                          java.util.Set<NameIdentifier> retainedAttributeNames)

Parameters:

relationBuffer - the relation to be subjected to grouping

groupAttributes - The specification of the groupings to be applied. Each entry consists of an attribute name for the relation-valued attribute in the result, and the set of attributes of this relation that that relation-typed attribute is to include.

retainedAttributeNames - The set of attributes to retain from the input expression, which is also the set of attributes to group by

Returns:

the given relation, grouped together according to the specs provided in groupAttributes

validateExpressionDetails

public static GROUPInvocationResultDetails validateExpressionDetails(Heading heading,
                                                                     java.util.Map<NameIdentifier,java.util.Set<NameIdentifier>> groupAttributes,
                                                                     java.lang.String predicate,
                                                                     java.util.Collection<? extends KeyDef> inputKeySpecifications)
                                                              throws NonExistingAttributeException,
                                                                     GroupAttributeOverlapException,
                                                                     AttributeGroupedTwiceException

Parameters:

heading - The heading of the relation that is subjected to grouping

groupAttributes - The specification of the groupings to be applied. Each entry consists of an attribute name for the relation-valued attribute in the result, and the set of attributes of this relation that that relation-typed attribute is to include.

predicate - The predicate of which the input relation is the extension

inputKeySpecifications - The key specifications known to be satisfied by the input relation

Returns:

The heading of the result from applying grouping as specified to the given relation type

Throws:

NonExistingAttributeException - If an attribute is specified for inclusion in an RVA that does not exist in the input

GroupAttributeOverlapException - If an attribute name is used for specifying an output RVA that also appears in the heading of the input. Note that

AttributeGroupedTwiceException - If an attribute is specified for inclusion in more than one RVA

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