1/*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements.  See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License.  You may obtain a copy of the License at
8 *
9 *    http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18package org.apache.spark.sql
19
20import org.apache.spark.annotation.{Experimental, InterfaceStability}
21import org.apache.spark.sql.catalyst.plans.logical.LogicalPlan
22import org.apache.spark.sql.catalyst.rules.Rule
23
24/**
25 * :: Experimental ::
26 * Holder for experimental methods for the bravest. We make NO guarantee about the stability
27 * regarding binary compatibility and source compatibility of methods here.
28 *
29 * {{{
30 *   spark.experimental.extraStrategies += ...
31 * }}}
32 *
33 * @since 1.3.0
34 */
35@Experimental
36@InterfaceStability.Unstable
37class ExperimentalMethods private[sql]() {
38
39  /**
40   * Allows extra strategies to be injected into the query planner at runtime.  Note this API
41   * should be considered experimental and is not intended to be stable across releases.
42   *
43   * @since 1.3.0
44   */
45  @volatile var extraStrategies: Seq[Strategy] = Nil
46
47  @volatile var extraOptimizations: Seq[Rule[LogicalPlan]] = Nil
48
49}
50