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/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
*
* Licensed 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. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.cache.query;
/**
* @deprecated As of 6.6.1. Check {@link QueryService} for changes.
*
* Enumerated type for types of {@linkplain Index indexes}
*
* @author Eric Zoerner
* @since 4.0
*/
public class IndexType {
/**
* The index type of a functional index.
* A functional index is used for the comparison of some function
* of a region value with a constant, using a relational operator.
* The indexedExpression yields a value that is a Comparable. The "constant"
* that it is to be compared to is any expression that is not dependent
* on a value in the region. A simple example is an index on the
* indexedExpression "age". This would be used for a query that has the
* where clause "age < 55".
*
* The indexedExpression for a functional index can be any Comparable
* or any of the following primitive types:
* long int short byte char float double
*
* @see QueryService#createIndex(String, IndexType, String, String)
*/
public static final IndexType FUNCTIONAL
= new IndexType("FUNCTIONAL");
/**
* The index type of a hash index.
* A hash index is used for the comparison of some function
* of a region value with a constant, using a relational operator.
* The indexedExpression yields a value that is a Comparable. The "constant"
* that it is to be compared to is any expression that is not dependent
* on a value in the region. A simple example is an index on the
* indexedExpression "age". This would be used for a query that has the
* where clause "age = 55".
*
* The indexedExpression for a hash index can be any Comparable
* or any of the following primitive types:
* long int short byte char float double
*
* @see QueryService#createIndex(String, IndexType, String, String)
*/
public static final IndexType HASH
= new IndexType("HASH");
/**
* The index type of a primary key index. A primary key index uses the
* keys in the region itself. By creating a primary key index, you make
* the query service aware of the relationship between the values in the
* region and the keys in the region and enable the relationship to be
* used to optimize the execution of queries. For example, if the values
* in a region are employee objects and the keys in the region is the
* attribute empId on those employees, then you can create a primary key
* index on that region with the indexedExpression "empId".
*
* The type of the indexedExpression for a primary key index can be any
* object type. Just as in a Region, the lookup is based on the implementation
* of the equals and hashCode methods in the
* object.
*
* @see QueryService#createIndex(String, IndexType, String, String)
*/
public static final IndexType PRIMARY_KEY = new IndexType("PRIMARY_KEY");
//public static final IndexType MAP_INDEX = new IndexType("MAP_INDEX");
private String name;
/** Creates a new instance of IndexType */
private IndexType(String name) {
this.name = name;
}
/**
* Return the index type as a String
* @return the String representation of this IndexType
*/
@Override
public String toString() {
return this.name;
}
}