com.persistit

Enum Transaction.CommitPolicy

java.lang.Object

java.lang.Enum<Transaction.CommitPolicy>

com.persistit.Transaction.CommitPolicy

All Implemented Interfaces:

Serializable, Comparable<Transaction.CommitPolicy>

Enclosing class:

Transaction

public static enum Transaction.CommitPolicy
extends Enum<Transaction.CommitPolicy>

Enum Constant Summary

Enum Constants

Enum Constant and Description
GROUP Every committed transaction is flushed to durable storage before Transaction.commit() returns.
HARD Every committed transaction is flushed synchronously to durable storage before the Transaction.commit() method returns.
SOFT The Transaction.commit() method returns before all updates have been written to durable storage.

Method Summary

Modifier and Type	Method and Description
static Transaction.CommitPolicy	valueOf(String name) Returns the enum constant of this type with the specified name.
static Transaction.CommitPolicy[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

SOFT

public static final Transaction.CommitPolicy SOFT

The Transaction.commit() method returns before all updates have been written to durable storage. This policy is a compromise that offers much better throughput, especially for sequential transactions, but does not provide durability for every committed transactions. Some recently committed transactions may be lost after a crash/recovery cycle.

HARD

public static final Transaction.CommitPolicy HARD

Every committed transaction is flushed synchronously to durable storage before the Transaction.commit() method returns. With this policy every transaction is durable before commit completes.

GROUP

public static final Transaction.CommitPolicy GROUP

Every committed transaction is flushed to durable storage before Transaction.commit() returns. Persistit attempts to coordinate the I/O needed to do this with other pending transactions; as a consequence, the commit method may pause briefly waiting for other transactions to reach their commit points. In general this option provides the slowest rate of sequential commits, but the aggregate transaction throughput across many threads may be much higher than with the HARD policy.

Method Detail

values

public static Transaction.CommitPolicy[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Transaction.CommitPolicy c : Transaction.CommitPolicy.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Transaction.CommitPolicy valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null