Use eclipselink.read-only
to retrieve read-only results back from a query.
Values
Table 4-35 describes this query hint's valid values.
Table 4-35 Valid Values for read-only
Value | Description |
---|---|
|
Retrieve read-only results from the query. |
|
(Default) Do not retrieve read-only results from the query. |
Usage
For non-transactional read operations, if the requested entity types are stored in the shared cache you can request that the shared instance be returned instead of a detached copy.
Note: You should never modify objects returned from the shared cache. |
Examples
Example 4-71 shows how to use this hint in a JPA query.
Example 4-71 Using read-only in a JPA Query
import org.eclipse.persistence.config.HintValues; import org.eclipse.persistence.config.QueryHints; query.setHint(QueryHints.READ_ONLY, HintValues.TRUE);
Example 4-72 shows how to use this hint with the @QueryHint
annotation.
Example 4-72 Using read-only in a @QueryHint Annotation
import org.eclipse.persistence.config.HintValues; import org.eclipse.persistence.config.QueryHints; @QueryHint(name=QueryHints.READ_ONLY, value=HintValues.TRUE);
See Also
For more information, see:
"Oracle EclipseLink JPA Performance Tuning" in Oracle Fusion Middleware Performance and Tuning Guide