flush

Use eclipselink.flush to specify if the query should flush the persistence context before executing.

Values

Table 4-9 describes this query hint's values.

Usage

If the query may access objects that have been changed in the persistence context, you must trigger a flush in order for the query to see the changes. If the query does not require seeing the changes, you should avoid the flush in order to improve performance.

You can also configure the flush-mode as a persistence unit property. See "flush-clear.cache" for more information.

You can also use conforming to query changes without requiring a flush. See "cache-usage" for more information.

Examples

import org.eclipse.persistence.config.HintValues;
 import org.eclipse.persistence.config.QueryHints;
 query.setHint("eclipselink.FLUSH", "TRUE");

import org.eclipse.persistence.config.HintValues;
 import org.eclipse.persistence.config.QueryHints;
 @QueryHint(name=QueryHints.FLUSH, value="TRUE");

See Also

For more information, see:

• "persistence-context.flush-mode"

• "flush-clear.cache"

• "EclipseLink" JPA Query Hints
  http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Basic_JPA_Development/Querying/Query_Hints

• "EclipseLink Caches" in Understanding EclipseLink

• "Querying" in Solutions Guide for EclispeLink

• "cache-usage.indirection-policy"

• "cache-usage"