| /* |
| * 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.geode.cache.query; |
| |
| import org.apache.geode.cache.Region; |
| |
| /** |
| * An index that is built over the data stored in a GemFire {@link Region}. |
| * <p> |
| * For a description of the types of indexes that GemFire currently supports, see |
| * {@linkplain IndexType}. |
| * <p> |
| * An index is specified using a name, indexedExpression, fromClause, and optionally a |
| * projectionAttributes. |
| * <p> |
| * The name uniquely identifies the index to for the statistics services in GemFire. |
| * <p> |
| * The indexedExpression is the lookup value for the index. The way that an indexedExpression is |
| * specified and used varies depending on the type of index. For more information, see |
| * {@linkplain IndexType}. |
| * <p> |
| * The fromClause specifies the collection(s) of objects that the index ranges over, and must |
| * contain one and only one region path. |
| * <p> |
| * The optional projectAttributes specifies a tranformation that is done on the values and is used |
| * for pre-computing a corresponding projection as defined in a query. |
| * |
| * @see QueryService#createIndex(String, IndexType, String, String) |
| * @see IndexType |
| * |
| * @since GemFire 4.0 |
| */ |
| public interface Index { |
| |
| /** |
| * Returns the unique name of this index |
| */ |
| String getName(); |
| |
| /** |
| * Get the index type |
| * |
| * @return the type of index |
| */ |
| IndexType getType(); |
| |
| /** |
| * The Region this index is on |
| * |
| * @return the Region for this index |
| */ |
| Region<?, ?> getRegion(); |
| |
| /** |
| * Get statistics information for this index. |
| * |
| * @throws UnsupportedOperationException for indexes created on Maps. Example: Index on Maps with |
| * expression p['key']. <br> |
| * On Map type indexes the stats are created at individual key level that can be viewed in |
| * VSD stats. |
| */ |
| IndexStatistics getStatistics(); |
| |
| /** |
| * Get the original fromClause for this index. |
| */ |
| String getFromClause(); |
| |
| |
| /** |
| * Get whether index is valid to be used in queries. |
| */ |
| default boolean isValid() { |
| return false; |
| } |
| |
| /** |
| * Get the canonicalized fromClause for this index. |
| */ |
| String getCanonicalizedFromClause(); |
| |
| /** |
| * Get the original indexedExpression for this index. |
| */ |
| String getIndexedExpression(); |
| |
| /** |
| * Get the canonicalized indexedExpression for this index. |
| */ |
| String getCanonicalizedIndexedExpression(); |
| |
| /** |
| * Get the original projectionAttributes for this expression. |
| * |
| * @return the projectionAttributes, or "*" if there were none specified at index creation. |
| */ |
| String getProjectionAttributes(); |
| |
| /** |
| * Get the canonicalized projectionAttributes for this expression. |
| * |
| * @return the projectionAttributes, or "*" if there were none specified at index creation. |
| */ |
| String getCanonicalizedProjectionAttributes(); |
| } |