@Partitioning

Use @Partitioning to configure a custom PartitioningPolicy.

Annotation Elements

Table 2-48 describes this annotation's elements.

Usage

Data partitioning allows for an application to scale its data across more than a single database machine. EclipseLink supports data partitioning at the Entity level to allow a different set of entity instances for the same class to be stored in a different physical database or different node within a database cluster. Both regular databases and clustered databases are supported. Data can be partitioned both horizontally and vertically.

Partitioning can be enabled on an entity, a relationship, a query, or a persistence unit.

Examples

Example 2-89 shows a custom partitioning policy.

@Entity
@Partitioning(name="order", partitioningClass=OrderPartitioningPolicy.class)
@public class Order {
    ...
}
 
public class OrderPartitioningPolicy extends PartitioningPolicy {
 
    public List<Accessor> getConnectionsForQuery(AbstractSession session, DatabaseQuery query, AbstractRecord arguments) {
        
        List<Accessor> accessors = new ArrayList<Accessor>(1);
        accessors.add(getAccessor(ACMEPool.leastBusy(), session, query, false));
        return accessors;
    }
}

See Also

For more information, see:

• "@Partitioned"

• "@HashPartitioning"

• "@PinnedPartitioning"

• "@RangePartitioning"

• "@ReplicationPartitioning"

• "@RoundRobinPartitioning"

• "@UnionPartitioning"

• "@ValuePartitioning"

• "partitioning"

• "Data Partitioning"
  http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Advanced_JPA_Development/Data_Partitioning

• EclipseLink Examples
  http://wiki.eclipse.org/EclipseLink/Examples/JPA/Partitioning