/*
* 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.slice;
import java.util.List;
import java.util.Map;
/**
* Policy to select one or more of the physical databases referred as
* <em>slice</em> in which a given query will be executed.
*
* @author Pinaki Poddar
*
* @see DistributionPolicy
*
*/
public interface QueryTargetPolicy {
/**
* Gets the name of the slices where a given query will be executed.
*
* @param query The query string to be executed.
* @param params the bound parameters of the query
* @param language the query language
* @param slices list of names of the active slices. The ordering of
* the list is either explicit <code>openjpa.slice.Names</code> property
* or implicit i.e. alphabetic order of available identifiers if
* <code>openjpa.slice.Names</code> is unspecified.
* @param context generic persistence context managing the given instance.
*
* @return identifier of the slices. This names must match one of the
* given slice names.
*
* @see DistributedConfiguration#getActiveSliceNames()
*/
String[] getTargets(String query, Map<Object,Object> params, String language,
List<String> slices, Object context);
}