1 /*
   2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package java.sql;
  26 
  27 /**
  28  * Interface used to indicate that this object represents a Sharding Key. A
  29  * {@code ShardingKey} instance is only guaranteed to be compatible with the
  30  * data source instance that it was derived from. A {@code ShardingKey} is
  31  * created using {@link ShardingKeyBuilder}.
  32  * <p>
  33  * The following example illustrates the use of {@link ShardingKeyBuilder} to
  34  * create a {@code ShardingKey}:
  35  * <pre>
  36  * {@code
  37  *
  38  *     DataSource ds = new MyDataSource();
  39  *     ShardingKey shardingKey = ds.createShardingKeyBuilder()
  40  *                           .subkey("abc", JDBCType.VARCHAR)
  41  *                           .subkey(94002, JDBCType.INTEGER)
  42  *                           .build();
  43  * }
  44  * </pre>
  45  * <p>
  46  *
  47  * A {@code ShardingKey} may also be used for specifying a
  48  * {@code superShardingKey}. Databases that support composite Sharding may use a
  49  * {@code superShardingKey} to specify a additional level of partitioning within
  50  * the Shard.
  51  * <p>
  52  * The following example illustrates the use of {@link ShardingKeyBuilder} to
  53  * create a {@code superShardingKey} for an eastern region with a
  54  * {@code ShardingKey} specified for the Pittsburgh branch office:
  55  * <pre>
  56  * {@code
  57  *
  58  *     DataSource ds = new MyDataSource();
  59  *     ShardingKey superShardingKey = ds.createShardingKeyBuilder()
  60  *                           .subkey("EASTERN_REGION", JDBCType.VARCHAR)
  61  *                           .build();
  62  *     ShardingKey shardingKey = ds.createShardingKeyBuilder()
  63  *                           .subkey("PITTSBURGH_BRANCH", JDBCType.VARCHAR)
  64  *                           .build();
  65  *     Connection con = ds.createConnectionBuilder()
  66  *                           .superShardingKey(superShardingKey)
  67  *                           .shardingKey(shardingKey)
  68  *                           .build();
  69  * }
  70  * </pre>
  71  *
  72  * @since 9
  73  */
  74 public interface ShardingKey {
  75 
  76 }