org.exolab.castor.jdo.drivers
Class MaxKeyGeneratorFactory
java.lang.Object
org.exolab.castor.jdo.drivers.MaxKeyGeneratorFactory
- KeyGeneratorFactory
public final class MaxKeyGeneratorFactory
extends java.lang.Object
MAX key generator factory.
The short name of this key generator is "MAX".
It uses the following alrorithm: the maximum value of the primary
key is fetched and the correspondent record is locked until the end
of transaction, generator returns (max + 1).
The lock guarantees that key generators of concurrent transactions
will not use this key value, so DuplicateKeyException is impossible.
If the table is empty, generator returns 1, no lock is put,
DuplicateKeyException is possible.
$Revision: 1.1.1.1 $ $Date: 2003/03/03 07:08:13 $
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