b20754d9ee
### What changes were proposed in this pull request? Document updated for `CACHE TABLE` & `UNCACHE TABLE` ### Why are the changes needed? Cache table creates a temp view while caching data using `CACHE TABLE name AS query`. `UNCACHE TABLE` does not remove this temp view. These things were not mentioned in the existing doc for `CACHE TABLE` & `UNCACHE TABLE`. ### Does this PR introduce any user-facing change? Document updated for `CACHE TABLE` & `UNCACHE TABLE` command. ### How was this patch tested? Manually Closes #27090 from iRakson/SPARK-27545. Lead-authored-by: root1 <raksonrakesh@gmail.com> Co-authored-by: iRakson <raksonrakesh@gmail.com> Signed-off-by: Wenchen Fan <wenchen@databricks.com>
52 lines
1.8 KiB
Markdown
52 lines
1.8 KiB
Markdown
---
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layout: global
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title: UNCACHE TABLE
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displayTitle: UNCACHE TABLE
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license: |
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Licensed to the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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this work for additional information regarding copyright ownership.
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The ASF licenses this file to You under the Apache License, Version 2.0
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(the "License"); you may not use this file except in compliance with
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the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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---
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### Description
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`UNCACHE TABLE` removes the entries and associated data from the in-memory and/or on-disk cache for a given table or view. The
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underlying entries should already have been brought to cache by previous `CACHE TABLE` operation. `UNCACHE TABLE` on a non-existent table throws an exception if `IF EXISTS` is not specified.
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### Syntax
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{% highlight sql %}
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UNCACHE TABLE [ IF EXISTS ] table_identifier
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{% endhighlight %}
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### Parameters
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<dl>
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<dt><code><em>table_identifier</em></code></dt>
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<dd>
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Specifies the table or view name to be uncached. The table or view name may be optionally qualified with a database name.<br><br>
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<b>Syntax:</b>
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<code>
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[ database_name. ] table_name
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</code>
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</dd>
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</dl>
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### Examples
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{% highlight sql %}
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UNCACHE TABLE t1;
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{% endhighlight %}
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### Related Statements
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* [CACHE TABLE](sql-ref-syntax-aux-cache-cache-table.html)
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* [CLEAR CACHE](sql-ref-syntax-aux-cache-clear-cache.html)
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* [REFRESH TABLE](sql-ref-syntax-aux-refresh-table.html)
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