spark-instrumented-optimizer/docs/sql-ref-syntax-aux-cache-refresh.md
root1 ce7a49f7fa [SPARK-30363][SQL][DOC] Add Documentation for refresh resources
### What changes were proposed in this pull request?
Documentation added for refresh resources command in spark-sql.

### Why are the changes needed?
Previously, only refresh table command was documented.

### Does this PR introduce any user-facing change?
Yes. Now users can access documentation for refresh resources command.

### How was this patch tested?
Manually.

Closes #27023 from iRakson/SPARK-30363.

Authored-by: root1 <raksonrakesh@gmail.com>
Signed-off-by: Sean Owen <srowen@gmail.com>
2019-12-31 09:36:41 -06:00

1.8 KiB

layout title displayTitle license
global REFRESH REFRESH 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.

Description

REFRESH is used to invalidate and refresh all the cached data (and the associated metadata) for all Datasets that contains the given data source path. Path matching is by prefix, i.e. "/" would invalidate everything that is cached.

Syntax

{% highlight sql %} REFRESH resource_path {% endhighlight %}

Parameters

resource_path
The path of the resource that is to be refreshed.

Examples

{% highlight sql %} -- The Path is resolved using the datasource's File Index.

CREATE TABLE test(ID INT) using parquet; INSERT INTO test SELECT 1000; CACHE TABLE test; INSERT INTO test SELECT 100; REFRESH "hdfs://path/to/table";

{% endhighlight %}