doc: Add Tuning Guide with shuffle configs

docs/source/index.rst

@@ -47,6 +47,7 @@ as a native runtime to achieve improvement in terms of query efficiency and quer
    Supported Data Types <user-guide/datatypes>
    Configuration Settings <user-guide/configs>
    Compatibility Guide <user-guide/compatibility>
+   Tuning Guide <user-guide/tuning>
 
 .. _toc.contributor-guide-links:
 .. toctree::

docs/source/user-guide/tuning.md

@@ -0,0 +1,60 @@
+<!---
+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.
+-->
+
+# Tuning Guide
+
+Comet provides some tuning options to help you get the best performance from your queries.
+
+
+## Shuffle
+
+Comet provides Comet shuffle features that can be used to improve the performance of your queries.
+The following sections describe the different shuffle options available in Comet.
+
+To enable Comet shuffle, set the following configuration in your Spark configuration:
+
+```
+spark.shuffle.manager=org.apache.spark.sql.comet.execution.shuffle.CometShuffleManager
+spark.comet.exec.shuffle.enabled=true
+```
+
+`spark.shuffle.manager` is a Spark static configuration which cannot be changed at runtime.
+It must be set before the Spark context is created. You can enable or disable Comet shuffle
+at runtime by setting `spark.comet.exec.shuffle.enabled` to `true` or `false`.
+Once it is disabled, Comet will fallback to the default Spark shuffle manager.
+
+### Columnar Shuffle
+
+By default, once `spark.comet.exec.shuffle.enabled` is enabled, Comet uses columnar shuffle
+to improve the performance of shuffle operations. Columnar shuffle supports HashPartitioning,
+RoundRobinPartitioning, RangePartitioning and SinglePartitioning.
+
+Columnar shuffle can be disabled by setting `spark.comet.columnar.shuffle.enabled` to `false`.
+
+### Native Shuffle
+
+Comet also provides a fully native shuffle implementation that can be used to improve the performance.
+To enable native shuffle, just disable `spark.comet.columnar.shuffle.enabled`.
+
+Native shuffle only supports HashPartitioning and SinglePartitioning.
+
+
+
+
+