public class Version extends Object implements oracle.kv.impl.util.FastExternalizable, Serializable
When a key-value pair is initially inserted in the KV Store, and each time
it is updated, it is assigned a unique version token. The version is always
returned by the put method, for example, put
, and is
also returned by get methods, for example, get
. The
version is important for two reasons:
putIfVersion
or deleteIfVersion
method. If the version specified does not match the
current version of the value in the KV Store, these methods will not
perform the update or delete operation and will return an indication of
failure. Optionally, they will also return the current version and/or
value so the client can retry the operation or take a different action.
Consistency
parameter to the read operation, for example, get
. See Consistency.Version
for more information.
It is important to be aware that the system may infrequently assign a new
Version to a key-value pair, for example, when migrating data for better
resource usage. Therefore, when using the putIfVersion
or deleteIfVersion
methods,
one cannot assume that the Version will remain constant until it is changed
by the application.
Modifier and Type | Method and Description |
---|---|
boolean |
equals(Object other) |
static Version |
fromByteArray(byte[] keyBytes)
Deserializes the given bytes that were returned earlier by
toByteArray() and returns the resulting Version. |
int |
hashCode() |
byte[] |
toByteArray()
Returns this Version as a serialized byte array, such that
fromByteArray(byte[]) may be used to reconstitute the Version. |
String |
toString() |
public byte[] toByteArray()
fromByteArray(byte[])
may be used to reconstitute the Version.public static Version fromByteArray(byte[] keyBytes)
toByteArray()
and returns the resulting Version.Copyright (c) 2011, 2015 Oracle and/or its affiliates. All rights reserved.