be.SIRAPRISE.typeimplementations

Class XMINUS_RELATION_RELATION_STRING

java.lang.Object

be.SIRAPRISE.typeimplementations.XMINUS_RELATION_RELATION_STRING

All Implemented Interfaces:

AggregationOperatorImplementation, OperatorGenerator, OperatorImplementation_V0104, OperatorImplementation_V0105, java.io.Externalizable, java.io.Serializable

public final class XMINUS_RELATION_RELATION_STRING
extends java.lang.Object
implements AggregationOperatorImplementation, OperatorGenerator

The relation XMINUS operator takes two arguments, both of a relation type. Both relation types must be the same. A third argument specifies the set of attributes that are to be treated in "range" mode when computing.
An invocation XMINUS(r1,r2,i) is equivalent to UNION(MINUS(r1,r2,i),MINUS(r2,r1,i),i).

Some examples of "temporal" XMINUS invocations and their result

r1	r2	i	result
REL { TUP {IV:[1-7]} }	REL { TUP {IV:[5-9]} }		REL { TUP {IV:[1-7] TUP {IV:[5-9]} }
REL { TUP {IV:[1-7]} }	REL { TUP {IV:[5-9]} }	IV	REL { TUP {IV:[1-4] TUP {IV:[8-9]} }

Author:

Erwin

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
XMINUS_RELATION_RELATION_STRING() Deprecated. - this constructor is available only for use in the context of the Externalizable machinery

Method Summary

Modifier and Type	Method and Description
AggregationOperatorImplementation	createInvocation(OperatorGeneratorArgument[] args) Creates an instance of the operator.
ValueBuffer	executeOperator(java.util.LinkedList<ValueBuffer> args) Performs the actual logic of the operator.
java.lang.String[]	getArgumentTypeNames() Gets the list of names of types of the needed argument values
ValueBuffer	getIdentityElement() Gets the identity element of the operator in its domain.
static AggregationOperatorImplementation	getInstance(Heading heading, java.util.LinkedList<NameIdentifier> treatAsRange) Gets an instance of the operator for the given heading and USING<> attributes
java.util.LinkedList<OperatorGeneratorArgumentType>	getOperatorGeneratorSignature() Gets the "generator signature" of the operator generator.
TypeDeclaration	getReturnTypeDeclaration() Gets the full type declaration of the type of the return value.
java.lang.String	getReturnTypeName() Gets the name of the type of the return value
java.lang.String	getSignature() Gets the name of the operator implemented by this implementation object
boolean	isDeterministic() Tells whether the operator is deterministic with respect to the arguments of its invocations.
void	readExternal(java.io.ObjectInput in)
void	writeExternal(java.io.ObjectOutput out)

Methods inherited from class java.lang.Object

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

Constructor Detail

XMINUS_RELATION_RELATION_STRING

@Deprecated
public XMINUS_RELATION_RELATION_STRING()

Deprecated. - this constructor is available only for use in the context of the Externalizable machinery

Creates the XMINUS_RELATION_RELATION_STRING

Method Detail

getInstance

public static AggregationOperatorImplementation getInstance(Heading heading,
                                                            java.util.LinkedList<NameIdentifier> treatAsRange)

Gets an instance of the operator for the given heading and USING<> attributes

Parameters:

heading - The heading

treatAsRange - The USING<> attributes

Returns:

an instance of the operator for the given heading and USING<> attributes

createInvocation

public final AggregationOperatorImplementation createInvocation(OperatorGeneratorArgument[] args)

Description copied from interface: OperatorGenerator

Creates an instance of the operator.

Specified by:

createInvocation in interface OperatorGenerator

Parameters:

args - The arguments from which the instance is to be created. There must be exactly as many arguments as there are elements in the list returned from OperatorGenerator.getOperatorGeneratorSignature(). The correspondence between OperatorGeneratorArgumentType values and OperatorGeneratorArgument types is given in the table below :

correspondence between OperatorGeneratorArgumentType values and OperatorGeneratorArgument types

OperatorGeneratorArgumentType value	OperatorGeneratorArgument type
EXPRESSION	NonScalarOperatorGeneratorExpressionArgument

Returns:

an instance of the operator

executeOperator

public ValueBuffer executeOperator(java.util.LinkedList<ValueBuffer> args)

Description copied from interface: OperatorImplementation_V0104

Performs the actual logic of the operator.

Specified by:

executeOperator in interface OperatorImplementation_V0104

Parameters:

args - the argument list. The list must hold as many ValueBuffer objects as there are arguments to the operator, and each ValueBuffer object holds a value for some argument to the operator. ValueBuffer objects on the list must appear in the same order as the operator argument declarations. Implementations have the option, but are not required, to do a check the conformance of the argument list (the argument count, notably) to the operator signature.

Returns:

A ValueBuffer object holding the result value of the operator execution in internal format.

getArgumentTypeNames

public java.lang.String[] getArgumentTypeNames()

Description copied from interface: OperatorImplementation_V0104

Gets the list of names of types of the needed argument values

Specified by:

getArgumentTypeNames in interface OperatorImplementation_V0104

Returns:

The names of the argument types

getIdentityElement

public ValueBuffer getIdentityElement()

Description copied from interface: AggregationOperatorImplementation

Gets the identity element of the operator in its domain.

Specified by:

getIdentityElement in interface AggregationOperatorImplementation

Returns:

The identity element.

getOperatorGeneratorSignature

public final java.util.LinkedList<OperatorGeneratorArgumentType> getOperatorGeneratorSignature()

Description copied from interface: OperatorGenerator

Gets the "generator signature" of the operator generator. There should be exactly as many OperatorGeneratorArgumentType values as there are in the result of the operator signature's getArgumentTypeNames method, and they should correspond, obviously, by ordinal position.

Specified by:

getOperatorGeneratorSignature in interface OperatorGenerator

Returns:

the "generator signature" of the operator generator.

getReturnTypeDeclaration

public TypeDeclaration getReturnTypeDeclaration()

Description copied from interface: OperatorImplementation_V0105

Gets the full type declaration of the type of the return value. Differs from the _V0104 getReturnTypeName() in that for nonscalar return types, this method also returns the heading, not just only the RELATION or TUPLE typename.

Specified by:

getReturnTypeDeclaration in interface OperatorImplementation_V0105

Returns:

the full type declaration of the type of the return value

getReturnTypeName

public java.lang.String getReturnTypeName()

Description copied from interface: OperatorImplementation_V0104

Gets the name of the type of the return value

Specified by:

getReturnTypeName in interface OperatorImplementation_V0104

Returns:

the name of the type of the return value

getSignature

public java.lang.String getSignature()

Description copied from interface: OperatorImplementation_V0104

Gets the name of the operator implemented by this implementation object

Specified by:

getSignature in interface OperatorImplementation_V0104

Returns:

the name of the operator implemented by this implementation object

isDeterministic

public boolean isDeterministic()

Description copied from interface: OperatorImplementation_V0104

Tells whether the operator is deterministic with respect to the arguments of its invocations. An operator is deterministic if and only if for any two distinct invocations, if all the argument values are the same, then the result value returned will also be the same. An example of a nondeterministic operators is RANDOM().

Specified by:

isDeterministic in interface OperatorImplementation_V0104

Returns:

true if the operator is deterministic.

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

Throws:

java.io.IOException

java.lang.ClassNotFoundException

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

Throws:

java.io.IOException