Class SequenceUpdater.BulkInsertUpdater

java.lang.Object

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

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

All Implemented Interfaces:

Cacheable, BulkInsertCounter

Enclosing class:

SequenceUpdater

public static final class SequenceUpdater.BulkInsertUpdater
extends SequenceUpdater
implements BulkInsertCounter

Implementation of SequenceUpdater for use with the bulk-insert optimization used by InsertResultSet. This BulkInsertUpdater doesn't really write to disk. It is assumed that the BulkInsertUpdater will only be used by the bulk-insert code, where the user has exclusive write-access on the table whose identity column is backed by the original SequenceUpdater. At the end of bulk-insert, the current value of the BulkInsertUpdater is written to disk by other code.

Nested Class Summary

Nested classes/interfaces inherited from class SequenceUpdater

SequenceUpdater.BulkInsertUpdater, SequenceUpdater.SyssequenceUpdater

Field Summary

Fields inherited from class SequenceUpdater

_dd, _sequenceGenerator, _uuidString

Constructor Summary

Constructors

Constructor	Description
BulkInsertUpdater()
BulkInsertUpdater(SequenceUpdater originalUpdater, boolean restart)

Method Summary

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

Methods inherited from class SequenceUpdater

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

Methods inherited from class Object

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

Methods inherited from interface BulkInsertCounter

getCurrentValueAndAdvance, peekAtCurrentValue

Constructor Details

BulkInsertUpdater

public BulkInsertUpdater()

BulkInsertUpdater

public BulkInsertUpdater(SequenceUpdater originalUpdater,
 boolean restart)

Method Details

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,
 Long oldValue,
 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.