Package org.apache.derby.impl.sql.catalog

Class SequenceUpdater.SyssequenceUpdater

java.lang.Object

org.apache.derby.impl.sql.catalog.SequenceUpdater

org.apache.derby.impl.sql.catalog.SequenceUpdater.SyssequenceUpdater

All Implemented Interfaces:

Cacheable

Enclosing class:

SequenceUpdater

public static final class SequenceUpdater.SyssequenceUpdater
extends SequenceUpdater

Specific implementation of SequenceUpdater for the sequences managed by SYSSEQUENCES.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.derby.impl.sql.catalog.SequenceUpdater

SequenceUpdater.BulkInsertUpdater, SequenceUpdater.SyssequenceUpdater

Field Summary

Fields

Modifier and Type	Field	Description
private RowLocation	_sequenceRowLocation

Fields inherited from class org.apache.derby.impl.sql.catalog.SequenceUpdater

_dd, _sequenceGenerator, _uuidString

Constructor Summary

Constructors

Constructor	Description
SyssequenceUpdater()
SyssequenceUpdater(DataDictionaryImpl dd)

Method Summary

Modifier and Type	Method	Description
protected SequenceGenerator	createSequenceGenerator(TransactionController readOnlyTC)	Initialize the sequence generator.
protected boolean	updateCurrentValueOnDisk(TransactionController tc, java.lang.Long oldValue, java.lang.Long newValue, boolean wait)	Update the sequence value on disk.

Methods inherited from class org.apache.derby.impl.sql.catalog.SequenceUpdater

clean, clearIdentity, createIdentity, getBulkInsertUpdater, getCurrentValueAndAdvance, getIdentity, isDirty, makePreallocator, peekAtCurrentValue, reset, setIdentity, updateCurrentValueOnDisk

Methods inherited from class java.lang.Object

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

Field Detail

_sequenceRowLocation

private RowLocation _sequenceRowLocation

Constructor Detail

SyssequenceUpdater

public SyssequenceUpdater()

SyssequenceUpdater

public SyssequenceUpdater(DataDictionaryImpl dd)

Method Detail

createSequenceGenerator

protected SequenceGenerator createSequenceGenerator(TransactionController readOnlyTC)
                                             throws StandardException

Description copied from class: SequenceUpdater

Initialize the sequence generator. Work is done inside a read-only subtransaction of the session's execution transaction.

Specified by:

createSequenceGenerator in class SequenceUpdater

Throws:

StandardException

updateCurrentValueOnDisk

protected boolean updateCurrentValueOnDisk(TransactionController tc,
                                           java.lang.Long oldValue,
                                           java.lang.Long newValue,
                                           boolean wait)
                                    throws StandardException

Description copied from class: SequenceUpdater

Update the sequence value on disk. This method does its work in a subtransaction of the user's execution transaction.

Specified by:

updateCurrentValueOnDisk in class SequenceUpdater

Parameters:

tc - The transaction to use

oldValue - Expected value on disk for this sequence

newValue - The value to poke into the system table backing this sequence

wait - Whether to wait for a lock

Returns:

Returns true if the value was successfully updated, false if we lost a race with another session.

Throws:

StandardException - May throw an exception if a lock can't be obtained.