CacheIndex (EclipseLink Core 4.0.2 API)

```
@Target({METHOD,FIELD,TYPE})
@Retention(RUNTIME)
@Repeatable(CacheIndexes.class)
public @interface CacheIndex
```
Allow a cache index to be define. A cache index allow singleResult queries to obtain a cache hit when querying on the indexed fields. resultList queries cannot obtain cache hits, as it is unknown if all of the objects are in memory, (unless the cache usage query hint is used). The index should be unique, but if not unique, the first indexed object will be returned. Cache indexes are only relevant when caching is enabled. The @CacheIndex can be defined on a Entity class, or on an attribute. The column is defaulted when defined on a attribute.

Since:

EclipseLink 2.4

Author:

James Sutherland

Optional Element Summary

Optional Elements
Modifier and Type	Optional Element	Description
`String[]`	`columnNames`	Specify the set of columns to define the index on.
`boolean`	`updateable`	Specify if the indexed field is updateable.

- Element Detail
  - columnNames
```
String[] columnNames
```
    Specify the set of columns to define the index on. Not required when annotated on a field/method.
    
    Default:
    
    {}
- - updateable
```
boolean updateable
```
    Specify if the indexed field is updateable. If updateable the object will be re-indexed on each update/refresh.
    
    Default:
    
    true