spark-instrumented-optimizer/docs/sql-ref-syntax-aux-cache-refresh.md
Huaxin Gao a75dc80a76 [SPARK-31636][SQL][DOCS] Remove HTML syntax in SQL reference
### What changes were proposed in this pull request?
Remove the unneeded embedded inline HTML markup by using the basic markdown syntax.
Please see #28414

### Why are the changes needed?
Make the doc cleaner and easily editable by MD editors.

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
Manually build and check

Closes #28451 from huaxingao/html_cleanup.

Authored-by: Huaxin Gao <huaxing@us.ibm.com>
Signed-off-by: Sean Owen <srowen@gmail.com>
2020-05-10 12:57:25 -05:00

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Markdown

---
layout: global
title: REFRESH
displayTitle: REFRESH
license: |
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
```sql
REFRESH resource_path
```
### Parameters
* **resource_path**
The path of the resource that is to be refreshed.
### Examples
```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";
```
### Related Statements
* [CACHE TABLE](sql-ref-syntax-aux-cache-cache-table.html)
* [CLEAR CACHE](sql-ref-syntax-aux-cache-clear-cache.html)
* [UNCACHE TABLE](sql-ref-syntax-aux-cache-uncache-table.html)
* [REFRESH TABLE](sql-ref-syntax-aux-refresh-table.html)