Class UniqueIndexSortObserver

java.lang.Object

org.apache.derby.impl.sql.execute.BasicSortObserver

org.apache.derby.impl.sql.execute.UniqueIndexSortObserver

All Implemented Interfaces:

SortObserver

class UniqueIndexSortObserver
extends BasicSortObserver

Unique index aggregator. Enforces uniqueness when creating a unique index or constraint.

Field Summary

Fields

Modifier and Type	Field	Description
private final UUID	constraintId
private final boolean	deferrable
private final boolean	deferred
private BackingStoreHashtable	deferredDuplicates
private final String	indexOrConstraintName
private final LanguageConnectionContext	lcc
private final String	tableName

Fields inherited from class BasicSortObserver

distinct, doClone

Constructor Summary

Constructors

Constructor	Description
UniqueIndexSortObserver(LanguageConnectionContext lcc, UUID constraintId, boolean doClone, boolean deferrable, boolean deferred, String indexOrConstraintName, ExecRow execRow, boolean reuseWrappers, String tableName)

Method Summary

Modifier and Type	Method	Description
boolean	deferrable()	Overridden by subclasses that observe sorters with uniqueness checking.
boolean	deferred()	Overridden by subclasses that observe sorters with uniqueness checking.
DataValueDescriptor[]	insertDuplicateKey(DataValueDescriptor[] in, DataValueDescriptor[] dup)	Called prior to inserting a duplicate sort key.
void	rememberDuplicate(DataValueDescriptor[] row)	Overridden by subclasses that observe sorters with uniqueness checking.

Methods inherited from class BasicSortObserver

addToFreeList, getArrayClone, insertNonDuplicateKey

Methods inherited from class Object

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

Field Details

deferrable

private final boolean deferrable

deferred

private final boolean deferred

indexOrConstraintName

private final String indexOrConstraintName

tableName

private final String tableName

lcc

private final LanguageConnectionContext lcc

constraintId

private final UUID constraintId

deferredDuplicates

private BackingStoreHashtable deferredDuplicates

Constructor Details

UniqueIndexSortObserver

public UniqueIndexSortObserver(LanguageConnectionContext lcc,
 UUID constraintId,
 boolean doClone,
 boolean deferrable,
 boolean deferred,
 String indexOrConstraintName,
 ExecRow execRow,
 boolean reuseWrappers,
 String tableName)

Method Details

insertDuplicateKey

public DataValueDescriptor[] insertDuplicateKey(DataValueDescriptor[] in,
 DataValueDescriptor[] dup)
                                         throws StandardException

Description copied from class: BasicSortObserver

Called prior to inserting a duplicate sort key.

Specified by:

insertDuplicateKey in interface SortObserver

Overrides:

insertDuplicateKey in class BasicSortObserver

Parameters:

in - the current row that the sorter is on the verge of retaining. It is a duplicate of existingRow.

dup - the row that is already in the the sorter which is a duplicate of insertRow

Returns:

the row to be inserted by the sorter. If null, then nothing is inserted by the sorter. Distinct sorts will want to return null.

Throws:

StandardException - never thrown

deferred

public boolean deferred()

Description copied from interface: SortObserver

Overridden by subclasses that observe sorters with uniqueness checking.

Specified by:

deferred in interface SortObserver

Overrides:

deferred in class BasicSortObserver

Returns:

true if constraint mode of the index's constraint is effectively deferred. Any SortObserver implementations that implement uniqueness checking need to keep track of this information.

deferrable

public boolean deferrable()

Description copied from interface: SortObserver

Overridden by subclasses that observe sorters with uniqueness checking.

Specified by:

deferrable in interface SortObserver

Overrides:

deferrable in class BasicSortObserver

Returns:

true if the index's constraint is deferrable. Any SortObserver implementations that implement uniqueness checking need to keep track of this information.

rememberDuplicate

public void rememberDuplicate(DataValueDescriptor[] row)
                       throws StandardException

Description copied from interface: SortObserver

Overridden by subclasses that observe sorters with uniqueness checking. Will be called by sorters iff deferrable() and deferred() and uniqueness violation, so implementations that sometimes return true to these must implement this method to save duplicate information till commit time.

Specified by:

rememberDuplicate in interface SortObserver

Overrides:

rememberDuplicate in class BasicSortObserver

Parameters:

row - data of offending key

Throws:

StandardException - standard error policy