org.apache.openjpa.kernel.QueryHints Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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* specific language governing permissions and limitations
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*/
package org.apache.openjpa.kernel;
/**
* Standard query hint keys.
*/
public interface QueryHints {
// These keys are directly handled in {@link QueryImpl} class.
// Declaring a public static final String variable in this class will
// make it register as a supported hint key
// if you do not want that then annotate as {@link Reflectable(false)}.
String HINT_SUBCLASSES = "openjpa.Subclasses";
String HINT_FILTER_LISTENER = "openjpa.FilterListener";
String HINT_FILTER_LISTENERS = "openjpa.FilterListeners";
String HINT_AGGREGATE_LISTENER = "openjpa.AggregateListener";
String HINT_AGGREGATE_LISTENERS = "openjpa.AggregateListeners";
/**
* Hint to specify the number of rows to optimize for.
*/
String HINT_RESULT_COUNT = "openjpa.hint.OptimizeResultCount";
/**
* Hints to signal that the JPQL/SQL query string contains a parameter
* marker ? character. By default, the query string is parsed
* to count number of parameters assuming that all ? characters
* designate a bind parameter. This assumption makes the parse faster.
*/
String HINT_PARAM_MARKER_IN_QUERY = "openjpa.hint.ParameterMarkerInQuery";
/**
* A directive to invalidate any prepared SQL that might have been cached
* against a JPQL query. The target SQL corresponding to a JPQL depends on
* several context parameters such as fetch configuration, lock mode etc.
* If a query is executed repeatedly and hence its SQL is cached for faster
* execution then if any of the contextual parameters change across query
* execution then the user must supply this hint to invalidate the cached
* SQL query.
* The alternative to monitor any such change for automatic invalidation
* has a constant performance penalty for the frequent use case where a
* query is repeatedly executed in different persistent context with the
* same fetch plan or locking.
*
* @see #HINT_IGNORE_PREPARED_QUERY
*/
String HINT_INVALIDATE_PREPARED_QUERY = "openjpa.hint.InvalidatePreparedQuery";
/**
* A directive to ignore any prepared SQL that might have been cached
* against a JPQL query. The target SQL corresponding to a JPQL depends on
* several context parameters such as fetch configuration, lock mode etc.
* If a query is executed repeatedly and hence its SQL is cached for faster
* execution then if any of the contextual parameters change across query
* execution then the user must supply this hint to ignore the cached
* SQL query for the current execution.
* This is in contrast with invalidation hint that removes the cached
* version from cache altogether.
*
* The cached SQL is retained and subsequent execution of the same query
* string without this hint will reuse the cached SQL.
*
* @see #HINT_INVALIDATE_PREPARED_QUERY
*/
String HINT_IGNORE_PREPARED_QUERY = "openjpa.hint.IgnorePreparedQuery";
/**
* A directive to ignore any cached finder query for find() operation.
* The cached entry, if any, remains in the cache.
*/
String HINT_IGNORE_FINDER = "openjpa.hint.IgnoreFinder";
/**
* A directive to invalidate any cached finder query.
*/
String HINT_INVALIDATE_FINDER = "openjpa.hint.InvalidateFinder";
/**
* A directive to overwrite a cached finder query by a new query.
*/
String HINT_RECACHE_FINDER =
"openjpa.hint.RecacheFinder";
/**
* A boolean directive to relax checking of binding parameter value and the predicate
* it binds to.
*/
String HINT_RELAX_BIND_PARAM_TYPE_CHECK = "openjpa.hint.RelaxParameterTypeChecking";
/**
* A boolean directive to generate literal directly into the SQL statement instead of using position parameter,
* if possible.
*/
String HINT_USE_LITERAL_IN_SQL = "openjpa.hint.UseLiteralInSQL";
}