query-results-cache.type

Use eclipselink.query-results-cache.type to set the cache type used for the query's results cache.

Values

Table 4-33 describes this query hint's values.

Table 4-33 Valid Values for query-results-cache.type

Value	Description
Cache	(Default) Fixed size LRU cache (`CacheIdentityMap`)
Full	Provides full caching and guaranteed identity.
Hard_Weak	Similar to SOFT_WEAK, except that it uses hard references in the sub-cache.
None	No caching.
Soft	Similar to FULL, except the map holds the objects using soft references.
Soft_Weak	Similar to WEAK, except it maintains a most-frequently-used sub-cache.
Weak	Similar to FULL, except the map holds the objects using weak references.

Usage

Examples

Example 4-67 shows how to use this hint in a JPA query.

Example 4-67 Using query-results-cache.type in a JPA Query

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

Example 4-68 shows how to use this hint with the @QueryHint annotation.

Example 4-68 Using query-results-cache.type in a @QueryHint Annotation

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

See Also

For more information, see:

"@Cache"
"Caching Overview"
http://wiki.eclipse.org/EclipseLink/UserGuide/JPA/Basic JPA Development/Caching/Caching Overview
"EclipseLink Caches" in the Understanding EclipseLink
"Scaling EclipseLink Applications in Clusters" in Solutions Guide for EclispeLink