Class UniqueWithDuplicateNullsExternalSortFactory

java.lang.Object

org.apache.derby.impl.store.access.sort.ExternalSortFactory

org.apache.derby.impl.store.access.sort.UniqueWithDuplicateNullsExternalSortFactory

All Implemented Interfaces:

ModuleControl, ModuleSupportable, MethodFactory, SortFactory, SortCostController

public class UniqueWithDuplicateNullsExternalSortFactory
extends ExternalSortFactory

Method factory to support sorting of Almost unique index. This class overrides getMergeSort of ExternalSortFactory to return UniqueWithDuplicateNullsMergeSort.

Field Summary

Fields

Modifier and Type	Field	Description
private static final String	IMPLEMENTATIONID

Fields inherited from class ExternalSortFactory

DEFAULT_MAX_MERGE_RUN, DEFAULT_MEM_USE

Fields inherited from interface SortFactory

MODULE

Constructor Summary

Constructors

Constructor	Description
UniqueWithDuplicateNullsExternalSortFactory()

Method Summary

Modifier and Type	Method	Description
protected MergeSort	getMergeSort()	Returns merge sort implementation.
String	primaryImplementationType()	Return the primary implementation type for this access method.
boolean	supportsImplementation(String implementationId)	Return whether this access method implements the implementation type given in the argument string.

Methods inherited from class ExternalSortFactory

boot, canSupport, close, createSort, defaultProperties, getSortCost, openSortCostController, primaryFormat, stop, supportsFormat

Methods inherited from class Object

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

Field Details

IMPLEMENTATIONID

private static final String IMPLEMENTATIONID

See Also:

• Constant Field Values

Constructor Details

UniqueWithDuplicateNullsExternalSortFactory

public UniqueWithDuplicateNullsExternalSortFactory()

Method Details

getMergeSort

protected MergeSort getMergeSort()

Description copied from class: ExternalSortFactory

Returns merge sort implementation. Extending classes can overide this method to customize sorting.

Overrides:

getMergeSort in class ExternalSortFactory

Returns:

MergeSort implementation

primaryImplementationType

public String primaryImplementationType()

Description copied from interface: MethodFactory

Return the primary implementation type for this access method. Although an access method may implement more than one implementation type, this is the expected one. The access manager will put the primary implementation type in a hash table for fast access.

Specified by:

primaryImplementationType in interface MethodFactory

Overrides:

primaryImplementationType in class ExternalSortFactory

See Also:

• MethodFactory.primaryImplementationType()

supportsImplementation

public boolean supportsImplementation(String implementationId)

Description copied from interface: MethodFactory

Return whether this access method implements the implementation type given in the argument string.

Specified by:

supportsImplementation in interface MethodFactory

Overrides:

supportsImplementation in class ExternalSortFactory

See Also:

• MethodFactory.supportsImplementation(String)