UnionPartitioning (EclipseLink 2.7.15, API Reference)

```
@Target({TYPE,METHOD,FIELD})
@Retention(RUNTIME)
public @interface UnionPartitioning
```
UnionPartitioning sends queries to all connection pools and unions the results. This is for queries or relationships that span partitions when partitioning is used, such as on a ManyToMany cross partition relationship.
Partitioning can be enabled on an Entity, relationship, query, or session/persistence unit. Partition policies are globally named to allow reuse, the partitioning policy must also be set using the @Partitioned annotation to be used.

See Also:

Partitioned, UnionPartitioningPolicy

Author:

James Sutherland

Since:

EclipseLink 2.2

Required Element Summary

Required Elements
Modifier and Type Required Element Description

java.lang.String name
The name of the partition policy, names must be unique for the persistence unit.

Optional Element Summary

Optional Elements
Modifier and Type	Optional Element	Description
`java.lang.String[]`	`connectionPools`	List of connection pool names to load balance across.
`boolean`	`replicateWrites`	Defines if write queries should be replicated.

- Element Detail
  - name
```
java.lang.String name
```
    The name of the partition policy, names must be unique for the persistence unit.
- - connectionPools
```
java.lang.String[] connectionPools
```
    List of connection pool names to load balance across. Defaults to all defined pools in the ServerSession.
    
    Default:
    
    {}
- - replicateWrites
```
boolean replicateWrites
```
    Defines if write queries should be replicated. Writes are normally not replicated when unioning, but can be for ManyToMany relationships, when the join table needs to be replicated.
    
    Default:
    
    false