com.sleepycat.client

Class STransactionConfig

java.lang.Object

com.sleepycat.client.STransactionConfig

public class STransactionConfig
extends java.lang.Object

Specifies the attributes of a database environment transaction.

For a user created instance, no attribute is set by default. In addition, calling the getter method of an unset attribute results in an IllegalStateException. To set an attribute, call the setter method of the attribute.

When used to begin a new transaction, system default values are used for unset attributes.

Constructor Summary

Constructors

Constructor and Description
STransactionConfig() Create an empty STransactionConfig with no attribute set.

Method Summary

Modifier and Type	Method and Description
boolean	getBulk() Return true if the Bulk attribute is set.
protected java.lang.Object	getField(F field) Return the value set on a specified field.
boolean	getNoSync() Return if the transaction is configured to not write or synchronously flush the log when it commits.
boolean	getNoWait() Return if the transaction is configured to not wait if a lock request cannot be immediately granted.
boolean	getReadCommitted() Return if the transaction is configured for read committed isolation.
boolean	getReadUncommitted() Return if read operations performed by the transaction are configured to return modified but not yet committed data.
boolean	getSnapshot() Return true if the transaction is configured for Snapshot Isolation.
boolean	getSync() Return if the transaction is configured to write and synchronously flush the log when it commits.
protected T	getThriftObj()
boolean	getWait() Return if the transaction is configured to wait if a lock request cannot be immediately granted.
boolean	getWriteNoSync() Return if the transaction is configured to write but not synchronously flush the log when it commits.
STransactionConfig	setBulk(boolean bulk) Configures the transaction to enable the transactional bulk insert optimization.
STransactionConfig	setNoSync(boolean noSync) Configure the transaction to not write or synchronously flush the log when it commits.
STransactionConfig	setNoWait(boolean noWait) Configure the transaction to not wait if a lock request cannot be immediately granted.
STransactionConfig	setReadCommitted(boolean readCommitted) Configure the transaction for read committed isolation.
STransactionConfig	setReadUncommitted(boolean readUncommitted) Configure read operations performed by the transaction to return modified but not yet committed data.
STransactionConfig	setSnapshot(boolean snapshot) This transaction will execute with snapshot isolation.
STransactionConfig	setSync(boolean sync) Configure the transaction to write and synchronously flush the log when it commits.
STransactionConfig	setWait(boolean wait) Configure the transaction to wait if a lock request cannot be immediately granted.
STransactionConfig	setWriteNoSync(boolean writeNoSync) Configure the transaction to write but not synchronously flush the log when it commits.

Methods inherited from class java.lang.Object

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

Constructor Detail

STransactionConfig

public STransactionConfig()

Create an empty STransactionConfig with no attribute set.

Method Detail

getBulk

public boolean getBulk()

Return true if the Bulk attribute is set.

Returns:

the current setting of the Bulk attribute.

setBulk

public STransactionConfig setBulk(boolean bulk)

Configures the transaction to enable the transactional bulk insert optimization. When this attribute is set, the transaction will avoid logging the contents of insertions on newly allocated database pages. In a transaction that inserts a large number of new records, the I/O savings of choosing this option can be significant. Users of this option should be aware of several issues. When the optimization is in effect, page allocations that extend the database file are logged as usual; this allows transaction aborts to work correctly, both online and during recovery. At commit time, the database's pages are flushed to disk, eliminating the need to roll-forward the transaction during normal recovery.

The bulk insert optimization is effective only for top-level transactions.

Parameters:

bulk - if true, configure the transaction to enable the bulk optimization.

Returns:

this

getNoSync

public boolean getNoSync()

Return if the transaction is configured to not write or synchronously flush the log when it commits.

Returns:

if the transaction is configured to not write or synchronously flush the log when it commits.

setNoSync

public STransactionConfig setNoSync(boolean noSync)

Configure the transaction to not write or synchronously flush the log when it commits.

This behavior may be set for a database environment using the SEnvironment.setConfig(SEnvironmentConfig) method. Any value specified to this method overrides that setting.

Parameters:

noSync - if true, transactions exhibit the ACI (atomicity, consistency, and isolation) properties, but not D (durability); that is, database integrity will be maintained, but if the server fails, it is possible some number of the most recently committed transactions may be undone during recovery. The number of transactions at risk is governed by how many log updates can fit into the log buffer, how often the server operating system flushes dirty buffers to disk, and how often the log is checkpointed.

Returns:

this

getSync

public boolean getSync()

Return if the transaction is configured to write and synchronously flush the log when it commits.

Returns:

if the transaction is configured to write and synchronously flush the log when it commits.

setSync

public STransactionConfig setSync(boolean sync)

Configure the transaction to write and synchronously flush the log when it commits.

Parameters:

sync - if true, transactions exhibit all the ACID (atomicity, consistency, isolation, and durability) properties.

Returns:

this

getWriteNoSync

public boolean getWriteNoSync()

Return if the transaction is configured to write but not synchronously flush the log when it commits.

Returns:

if the transaction is configured to not write or synchronously flush the log when it commits.

setWriteNoSync

public STransactionConfig setWriteNoSync(boolean writeNoSync)

Configure the transaction to write but not synchronously flush the log when it commits.

This behavior may be set for a database environment using the SEnvironment.setConfig(SEnvironmentConfig) method. Any value specified to this method overrides that setting.

Parameters:

writeNoSync - if true, transactions exhibit the ACI (atomicity, consistency, and isolation) properties, but not D (durability); that is, database integrity will be maintained, but if the server fails, it is possible some number of the most recently committed transactions may be undone during recovery. The number of transactions at risk is governed by how many log updates can fit into the log buffer, how often the server operating system flushes dirty buffers to disk, and how often the log is checkpointed.

Returns:

this

getNoWait

public boolean getNoWait()

Return if the transaction is configured to not wait if a lock request cannot be immediately granted.

Returns:

if the transaction is configured to not wait if a lock request cannot be immediately granted.

setNoWait

public STransactionConfig setNoWait(boolean noWait)

Configure the transaction to not wait if a lock request cannot be immediately granted.

Parameters:

noWait - if true, transactions will not wait if a lock request cannot be immediately granted, instead SDeadlockException will be thrown.

Returns:

this

getWait

public boolean getWait()

Return if the transaction is configured to wait if a lock request cannot be immediately granted.

Returns:

if the transaction is configured to wait if a lock request cannot be immediately granted.

setWait

public STransactionConfig setWait(boolean wait)

Configure the transaction to wait if a lock request cannot be immediately granted.

Parameters:

wait - if true, transactions will wait if a lock request cannot be immediately granted.

Returns:

this

getReadCommitted

public boolean getReadCommitted()

Return if the transaction is configured for read committed isolation.

Returns:

if the transaction is configured for read committed isolation.

setReadCommitted

public STransactionConfig setReadCommitted(boolean readCommitted)

Configure the transaction for read committed isolation.

This ensures the stability of the current data item read by the cursor but permits data read by this transaction to be modified or deleted prior to the commit of the transaction.

Parameters:

readCommitted - if true, configure the transaction for read committed isolation.

Returns:

this

getReadUncommitted

public boolean getReadUncommitted()

Return if read operations performed by the transaction are configured to return modified but not yet committed data.

Returns:

if read operations performed by the transaction are configured to return modified but not yet committed data.

setReadUncommitted

public STransactionConfig setReadUncommitted(boolean readUncommitted)

Configure read operations performed by the transaction to return modified but not yet committed data.

Parameters:

readUncommitted - if true, configure read operations performed by the transaction to return modified but not yet committed data.

Returns:

this

getSnapshot

public boolean getSnapshot()

Return true if the transaction is configured for Snapshot Isolation.

Returns:

true if the transaction is configured for Snapshot Isolation.

setSnapshot

public STransactionConfig setSnapshot(boolean snapshot)

This transaction will execute with snapshot isolation. For databases configured with SDatabaseConfig.setMultiversion(boolean), data values will be read as they are when the transaction begins, without taking read locks.

Updates operations performed in the transaction will cause a SDeadlockException to be thrown if data is modified between reading and writing it.

Parameters:

snapshot - if this transaction will execute with snapshot isolation

Returns:

this

getThriftObj

protected T getThriftObj()

getField

protected java.lang.Object getField(F field)
                             throws java.lang.IllegalStateException

Return the value set on a specified field. Throw IllegalStateException if the field is not set.

Parameters:

field - the field

Returns:

the field's value

Throws:

java.lang.IllegalStateException - if the field is not set