754f820035
## What changes were proposed in this pull request? Add AL2 license to metadata of all .md files. This seemed to be the tidiest way as it will get ignored by .md renderers and other tools. Attempts to write them as markdown comments revealed that there is no such standard thing. ## How was this patch tested? Doc build Closes #24243 from srowen/SPARK-26918. Authored-by: Sean Owen <sean.owen@databricks.com> Signed-off-by: Sean Owen <sean.owen@databricks.com>
42 lines
2.2 KiB
Markdown
42 lines
2.2 KiB
Markdown
---
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layout: global
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title: ORC Files
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displayTitle: ORC Files
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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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Since Spark 2.3, Spark supports a vectorized ORC reader with a new ORC file format for ORC files.
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To do that, the following configurations are newly added. The vectorized reader is used for the
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native ORC tables (e.g., the ones created using the clause `USING ORC`) when `spark.sql.orc.impl`
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is set to `native` and `spark.sql.orc.enableVectorizedReader` is set to `true`. For the Hive ORC
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serde tables (e.g., the ones created using the clause `USING HIVE OPTIONS (fileFormat 'ORC')`),
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the vectorized reader is used when `spark.sql.hive.convertMetastoreOrc` is also set to `true`.
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<table class="table">
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<tr><th><b>Property Name</b></th><th><b>Default</b></th><th><b>Meaning</b></th></tr>
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<tr>
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<td><code>spark.sql.orc.impl</code></td>
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<td><code>native</code></td>
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<td>The name of ORC implementation. It can be one of <code>native</code> and <code>hive</code>. <code>native</code> means the native ORC support that is built on Apache ORC 1.4. `hive` means the ORC library in Hive 1.2.1.</td>
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</tr>
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<tr>
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<td><code>spark.sql.orc.enableVectorizedReader</code></td>
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<td><code>true</code></td>
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<td>Enables vectorized orc decoding in <code>native</code> implementation. If <code>false</code>, a new non-vectorized ORC reader is used in <code>native</code> implementation. For <code>hive</code> implementation, this is ignored.</td>
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</tr>
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</table>
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