public class Sequence
extends java.lang.Object
Database.openSequence
method.Modifier and Type | Method and Description |
---|---|
void |
close()
Close a sequence.
|
long |
get(Transaction txn,
int delta)
Return the next available element in the sequence and changes the sequence
value by
delta . |
Database |
getDatabase()
Return the Database handle associated with this sequence.
|
DatabaseEntry |
getKey()
Return the DatabaseEntry used to open this sequence.
|
SequenceStats |
getStats(StatsConfig config)
Return statistical information about the sequence.
|
int |
printStats(StatsConfig config)
Print statistical information about the sequence to a specified output
channel (see the setMsgfile() method for more information), or passed to an
application callback function (see the setMsgcall() method for more
information).
|
public void close() throws DatabaseException
The sequence handle may not be used again after this method has been called, regardless of the method's success or failure.
DatabaseException
- if a failure occurs.public long get(Transaction txn, int delta) throws DatabaseException
delta
. The value of delta
must be
greater than zero. If there are enough cached values in the sequence
handle then they will be returned. Otherwise the next value will be
fetched from the database and incremented (decremented) by enough to cover
the delta
and the next batch of cached values.
The txn
handle must be null if the sequence handle was opened
with a non-zero cache size.
For maximum concurrency, a non-zero cache size should be specified prior to
opening the sequence handle, the txn
handle should be
null
, and SequenceConfig.setAutoCommitNoSync
should
be called to disable log flushes.
txn
- For a transactional database, an explicit transaction may be specified, or null
may be specified to use auto-commit. For a non-transactional database, null
must be specified.
delta
- the amount by which to increment or decrement the sequence
DatabaseException
- if a failure occurs.public Database getDatabase() throws DatabaseException
DatabaseException
- if a failure occurs.public DatabaseEntry getKey() throws DatabaseException
DatabaseException
- if a failure occurs.public SequenceStats getStats(StatsConfig config) throws DatabaseException
In the presence of multiple threads or processes accessing an active sequence, the information returned by this method may be out-of-date.
The getStats method cannot be transaction-protected. For this reason, it should be called in a thread of control that has no open cursors or active transactions.
config
- The statistics returned; if null, default statistics are returned.
DatabaseException
- if a failure occurs.public int printStats(StatsConfig config) throws DatabaseException
config
- The statistics returned; if null, default statistics are returned.
DatabaseException
- if a failure occurs.Copyright (c) 1996, 2019 Oracle and/or its affiliates. All rights reserved.