spark-instrumented-optimizer/docs/sql-ref-syntax-aux-cache-refresh-table.md
Huaxin Gao 492d5d174a [SPARK-32171][SQL][DOCS] Change file locations for use db and refresh table
### What changes were proposed in this pull request?

docs/sql-ref-syntax-qry-select-usedb.md -> docs/sql-ref-syntax-ddl-usedb.md
docs/sql-ref-syntax-aux-refresh-table.md -> docs/sql-ref-syntax-aux-cache-refresh-table.md

### Why are the changes needed?
usedb belongs to DDL. Its location should be consistent with other DDL commands file locations
similar reason for refresh table

### Does this PR introduce _any_ user-facing change?
before change, when clicking USE DATABASE, the side bar menu shows select commands
<img width="1200" alt="Screen Shot 2020-07-04 at 9 05 35 AM" src="https://user-images.githubusercontent.com/13592258/86516696-b45f8a80-bdd7-11ea-8dba-3a5cca22aad3.png">

after change, when clicking USE DATABASE, the side bar menu shows DDL commands
<img width="1120" alt="Screen Shot 2020-07-04 at 9 06 06 AM" src="https://user-images.githubusercontent.com/13592258/86516703-bf1a1f80-bdd7-11ea-8a90-ae7eaaafd44c.png">

before change, when clicking refresh table, the side bar menu shows Auxiliary statements
<img width="1200" alt="Screen Shot 2020-07-04 at 9 30 40 AM" src="https://user-images.githubusercontent.com/13592258/86516877-3d2af600-bdd9-11ea-9568-0a6f156f57da.png">

after change, when clicking refresh table, the side bar menu shows Cache statements
<img width="1199" alt="Screen Shot 2020-07-04 at 9 35 21 AM" src="https://user-images.githubusercontent.com/13592258/86516937-b4f92080-bdd9-11ea-8ad1-5f5a7f58d76b.png">

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

Closes #28995 from huaxingao/docs_fix.

Authored-by: Huaxin Gao <huaxing@us.ibm.com>
Signed-off-by: Huaxin Gao <huaxing@us.ibm.com>
2020-07-04 19:01:07 -07:00

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2.1 KiB
Markdown

---
layout: global
title: REFRESH TABLE
displayTitle: REFRESH TABLE
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 TABLE` statement invalidates the cached entries, which include data
and metadata of the given table or view. The invalidated cache is populated in
lazy manner when the cached table or the query associated with it is executed again.
### Syntax
```sql
REFRESH [TABLE] table_identifier
```
### Parameters
* **table_identifier**
Specifies a table name, which is either a qualified or unqualified name that designates a table/view. If no database identifier is provided, it refers to a temporary view or a table/view in the current database.
**Syntax:** `[ database_name. ] table_name`
### Examples
```sql
-- The cached entries of the table will be refreshed
-- The table is resolved from the current database as the table name is unqualified.
REFRESH TABLE tbl1;
-- The cached entries of the view will be refreshed or invalidated
-- The view is resolved from tempDB database, as the view name is qualified.
REFRESH TABLE tempDB.view1;
```
### 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](sql-ref-syntax-aux-cache-refresh.html)