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Berkeley
DB Java Edition version 1.7.1 |
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java.lang.Objectcom.sleepycat.je.Transaction
The Transaction object is the handle for a transaction. Methods off the transaction handle are used to configure, abort and commit the transaction. Transaction handles are provided to other Berkeley DB methods in order to transactionally protect those operations.
Transaction handles are free-threaded; transactions handles may
be used concurrently by multiple threads. Once the Transaction.abort
or Transaction.commit
methods are called, the handle may not be accessed again, regardless of
the success or failure of the method.
To obtain a transaction with default attributes:
To customize the attributes of a transaction:Transaction txn = myEnvironment.beginTransaction(null, null);
TransactionConfig config = new TransactionConfig(); config.setDirtyRead(true); Transaction txn = myEnvironment.beginTransaction(null, config);
Method Summary | |
void |
abort()
Cause an abnormal termination of the transaction. |
void |
commit()
End the transaction. |
void |
commitNoSync()
End the transaction, not committing synchronously. |
void |
commitSync()
End the transaction, committing synchronously. |
void |
commitWriteNoSync()
End the transaction, writing but not flushing the log. |
long |
getId()
Return the transaction's unique ID. |
String |
getName()
Get the user visible name for the transaction. |
void |
setLockTimeout(long timeOut)
Configure the lock request timeout value for the transaction. |
void |
setName(String name) Set the user visible name for the transaction. |
void |
setTxnTimeout(long timeOut)
Configure the timeout value for the transaction lifetime. |
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Method Detail |
public long getId() throws DatabaseException
DatabaseException
- if a
failure occurs.
public void abort() throws DatabaseException
The log is played backward, and any necessary undo operations are done. Before Transaction.abort returns, any locks held by the transaction will have been released.
In the case of nested transactions, aborting a parent transaction causes all children (unresolved or not) of the parent transaction to be aborted.
All cursors opened within the transaction must be closed before the transaction is aborted.
After Transaction.abort has been called, regardless of its
return, the Transaction
handle
may not be accessed again.
DatabaseException
- if a
failure occurs.
public void commit() throws DatabaseException
If the environment is not configured for synchronous commit, the commit will not necessarily have been committed to stable storage before the call returns. This means the transaction will exhibit the ACI (atomicity, consistency, and isolation) properties, but not D (durability); that is, database integrity will be maintained, but it is possible this transaction may be undone during recovery.
All cursors opened within the transaction must be closed before the transaction is committed.
After this method returns the Transaction
handle
may not be accessed again, regardless of the method's success or
failure. If the method encounters an error, the transaction and all
child transactions of the transaction will have been aborted when the
call returns.
DatabaseException
- if a
failure occurs.
public void commitSync() throws DatabaseException
This behavior is the default for database environments unless
otherwise configured using the EnvironmentConfig.setTxnNoSync
method. This behavior may also be set for a single transaction using
the Environment.beginTransaction
method. Any value specified to this method overrides both of those
settings.
All cursors opened within the transaction must be closed before the transaction is committed.
After this method returns the Transaction
handle
may not be accessed again, regardless of the method's success or
failure. If the method encounters an error, the transaction and all
child transactions of the transaction will have been aborted when the
call returns.
DatabaseException
- if a
failure occurs.
public void commitNoSync() throws DatabaseException
This behavior may be set for a database environment using the EnvironmentConfig.setTxnNoSync
method or for a single transaction using the Environment.beginTransaction
method. Any value specified to this method overrides both of those
settings.
All cursors opened within the transaction must be closed before the transaction is committed.
After this method returns the Transaction
handle
may not be accessed again, regardless of the method's success or
failure. If the method encounters an error, the transaction and all
child transactions of the transaction will have been aborted when the
call returns.
DatabaseException
- if a
failure occurs.
public void commitWriteNoSync() throws DatabaseException
This behavior may be set for a database environment using the EnvironmentConfig.setTxnWriteNoSync
method or for a single transaction using the Environment.beginTransaction
method. Any value specified to this method overrides both of those
settings.
All cursors opened within the transaction must be closed before the transaction is committed.
After this method returns the Transaction
handle
may not be accessed again, regardless of the method's success or
failure. If the method encounters an error, the transaction and all
child transactions of the transaction will have been aborted when the
call returns.
DatabaseException
- if a
failure occurs.
public void setTxnTimeout(long timeOut) throws DatabaseException
If the transaction runs longer than this time, the transaction
may may throw DatabaseException
.
Timeouts are checked whenever a thread of control blocks on a lock or when deadlock detection is performed. For this reason, the accuracy of the timeout depends on how often deadlock detection is performed.
timeOut
- The timeout value for the transaction
lifetime, in microseconds. As the value is an unsigned 32-bit number
of microseconds, the maximum timeout is roughly 71 minutes. A value of
0 disables timeouts for the transaction.
This method may be called at any time during the life of the application.
DatabaseException
- if a
failure occurs.
public void setLockTimeout(long timeOut) throws DatabaseException
If a lock request cannot be granted in this time, the
transaction may throw DatabaseException
.
Timeouts are checked whenever a thread of control blocks on a lock or when deadlock detection is performed. For this reason, the accuracy of the timeout depends on how often deadlock detection is performed.
timeOut
- The lock request timeout value for the
transaction, in microseconds. As the value is an unsigned 32-bit
number of microseconds, the maximum timeout is roughly 71 minutes. A
value of 0 disables timeouts for the transaction.
This method may be called at any time during the life of the application.
DatabaseException
- if a
failure occurs.
public void setName(String name)
name
- The user visible name for the
transaction.
public String getName()
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Berkeley
DB Java Edition version 1.7.1 |
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