Github user walterddr commented on a diff in the pull request:

    https://github.com/apache/flink/pull/5913#discussion_r184860963
  
    --- Diff: docs/dev/table/sqlClient.md ---
    @@ -0,0 +1,539 @@
    +---
    +title: "SQL Client"
    +nav-parent_id: tableapi
    +nav-pos: 100
    +is_beta: true
    +---
    +<!--
    +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.
    +-->
    +
    +
    +Although Flink’s Table & SQL API allows to declare queries in the SQL 
language. A SQL query needs to be embedded within a table program that is 
written either in Java or Scala. The table program needs to be packaged with a 
build tool before it can be submitted to a cluster. This limits the usage of 
Flink to mostly Java/Scala programmers.
    +
    +The *SQL Client* aims to provide an easy way of writing, debugging, and 
submitting table programs to a Flink cluster without a single line of code. The 
*SQL Client CLI* allows for retrieving and visualizing real-time results from 
the running distributed application on the command line.
    +
    +<a href="{{ site.baseurl }}/fig/sql_client_demo.gif"><img class="offset" 
src="{{ site.baseurl }}/fig/sql_client_demo.gif" alt="Animated demo of the 
Flink SQL Client CLI running table programs on a cluster" width="80%" /></a>
    +
    +**Note:** The SQL Client is in an early developement phase. Even though 
the application is not production-ready yet, it can be a quite useful tool for 
prototyping and playing around with Flink SQL. In the future, the community 
plans to extend its functionality by providing a REST-based [SQL Client 
Gateway](sqlClient.html#limitations--future).
    +
    +* This will be replaced by the TOC
    +{:toc}
    +
    +Getting Started
    +---------------
    +
    +This section describes how to setup and run your first Flink SQL program 
from the command-line. The SQL Client is bundled in the regular Flink 
distribution and thus runnable out of the box.
    +
    +The SQL Client requires a running Flink cluster where table programs can 
be submitted to. For more information about setting up a Flink cluster see the 
[deployment part of this documentation]({{ site.baseurl 
}}/ops/deployment/cluster_setup.html). If you simply want to try out the SQL 
Client, you can also start a local cluster with one worker using the following 
command:
    +
    +{% highlight bash %}
    +./bin/start-cluster.sh
    +{% endhighlight %}
    +
    +### Starting the SQL Client CLI
    +
    +The SQL Client scripts are also located in the binary directory of Flink. 
You can start the CLI by calling:
    +
    +{% highlight bash %}
    +./bin/sql-client.sh embedded
    +{% endhighlight %}
    +
    +This command starts the submission service and CLI embedded in one 
application process. By default, the SQL Client will read its configuration 
from the environment file located in `./conf/sql-client-defaults.yaml`. See the 
[next part](sqlClient.html#environment-files) for more information about the 
structure of environment files.
    +
    +### Running SQL Queries
    +
    +Once the CLI has been started, you can use the `HELP` command to list all 
available SQL statements. For validating your setup and cluster connection, you 
can enter your first SQL query and press the `Enter` key to execute it:
    +
    +{% highlight sql %}
    +SELECT 'Hello World'
    +{% endhighlight %}
    +
    +This query requires no table source and produces a single row result. The 
CLI will retrieve results from the cluster and visualize them. You can close 
the result view by pressing the `Q` key.
    +
    +The CLI supports **two modes** for maintaining and visualizing results.
    +
    +The *table mode* materializes results in memory and visualizes them in a 
regular, paginated table representation. It can be enabled by executing the 
following command in the CLI:
    +
    +{% highlight text %}
    +SET execution.result-mode=table
    +{% endhighlight %}
    +
    +The *changelog mode* does not materialize results and visualizes the 
result stream that is produced by a continuous query [LINK] consisting of 
insertions (`+`) and retractions (`-`).
    +
    +{% highlight text %}
    +SET execution.result-mode=changelog
    +{% endhighlight %}
    +
    +You can use the following query to see both result modes in action:
    +
    +{% highlight sql %}
    +SELECT name, COUNT(*) AS cnt FROM (VALUES ('Bob'), ('Alice'), ('Greg'), 
('Bob')) AS NameTable(name) GROUP BY name 
    +{% endhighlight %}
    +
    +This query performs a bounded word count example. The following sections 
explain how to read from table sources and configure other table program 
properties. 
    --- End diff --
    
    can we replace "following sections" with the actual link, docs might be 
updated later and the "following" statement might no longer be true


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