| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * 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, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| 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 <code>?</code> character. By default, the query string is parsed |
| * to count number of parameters assuming that all <code>?</code> 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"; |
| } |