<!DOCTYPE html><html lang="en"><head><meta charSet="utf-8"/><meta http-equiv="X-UA-Compatible" content="IE=edge"/><title>ORC Extension · Apache Druid</title><meta name="viewport" content="width=device-width, initial-scale=1.0"/><link rel="canonical" href="https://druid.apache.org/docs/latest/development/extensions-core/orc.html"/><meta name="generator" content="Docusaurus"/><meta name="description" content="&lt;!--"/><meta name="docsearch:language" content="en"/><meta name="docsearch:version" content="26.0.0" /><meta property="og:title" content="ORC Extension · Apache Druid"/><meta property="og:type" content="website"/><meta property="og:url" content="https://druid.apache.org/index.html"/><meta property="og:description" content="&lt;!--"/><meta property="og:image" content="https://druid.apache.org/img/druid_nav.png"/><meta name="twitter:card" content="summary"/><meta name="twitter:image" content="https://druid.apache.org/img/druid_nav.png"/><link rel="shortcut icon" href="/img/favicon.png"/><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/docsearch.js@2/dist/cdn/docsearch.min.css"/><link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/default.min.css"/><script async="" src="https://www.googletagmanager.com/gtag/js?id=UA-131010415-1"></script><script>
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<h2><a class="anchor" aria-hidden="true" id="orc-extension"></a><a href="#orc-extension" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>ORC extension</h2>
<p>This Apache Druid extension enables Druid to ingest and understand the Apache ORC data format.</p>
<p>The extension provides the <a href="/docs/latest/ingestion/data-formats.html#orc">ORC input format</a> and the <a href="/docs/latest/ingestion/data-formats.html#orc-hadoop-parser">ORC Hadoop parser</a>
for <a href="/docs/latest/ingestion/native-batch.html">native batch ingestion</a> and <a href="/docs/latest/ingestion/hadoop.html">Hadoop batch ingestion</a>, respectively.
Please see corresponding docs for details.</p>
<p>To use this extension, make sure to <a href="/docs/latest/development/extensions.html#loading-extensions">include</a> <code>druid-orc-extensions</code> in the extensions load list.</p>
<h3><a class="anchor" aria-hidden="true" id="migration-from-contrib-extension"></a><a href="#migration-from-contrib-extension" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Migration from 'contrib' extension</h3>
<p>This extension, first available in version 0.15.0, replaces the previous 'contrib' extension which was available until
0.14.0-incubating. While this extension can index any data the 'contrib' extension could, the JSON spec for the
ingestion task is <em>incompatible</em>, and will need modified to work with the newer 'core' extension.</p>
<p>To migrate to 0.15.0+:</p>
<ul>
<li>In <code>inputSpec</code> of <code>ioConfig</code>, <code>inputFormat</code> must be changed from <code>&quot;org.apache.hadoop.hive.ql.io.orc.OrcNewInputFormat&quot;</code> to
<code>&quot;org.apache.orc.mapreduce.OrcInputFormat&quot;</code></li>
<li>The 'contrib' extension supported a <code>typeString</code> property, which provided the schema of the
ORC file, of which was essentially required to have the types correct, but notably <em>not</em> the column names, which
facilitated column renaming. In the 'core' extension, column renaming can be achieved with
<a href="/docs/latest/ingestion/ingestion-spec.html#flattenspec"><code>flattenSpec</code></a>. For example, <code>&quot;typeString&quot;:&quot;struct&lt;time:string,name:string&gt;&quot;</code>
with the actual schema <code>struct&lt;_col0:string,_col1:string&gt;</code>, to preserve Druid schema would need replaced with:</li>
</ul>
<pre><code class="hljs css language-json">"flattenSpec": {
  "fields": [
    {
      "type": "path",
      "name": "time",
      "expr": "$._col0"
    },
    {
      "type": "path",
      "name": "name",
      "expr": "$._col1"
    }
  ]
  ...
}
</code></pre>
<ul>
<li>The 'contrib' extension supported a <code>mapFieldNameFormat</code> property, which provided a way to specify a dimension to
flatten <code>OrcMap</code> columns with primitive types. This functionality has also been replaced with
<a href="/docs/latest/ingestion/ingestion-spec.html#flattenspec"><code>flattenSpec</code></a>. For example: <code>&quot;mapFieldNameFormat&quot;: &quot;&lt;PARENT&gt;_&lt;CHILD&gt;&quot;</code>
for a dimension <code>nestedData_dim1</code>, to preserve Druid schema could be replaced with</li>
</ul>
<pre><code class="hljs css language-json">"flattenSpec": {
 "fields": [
   {
     "type": "path",
     "name": "nestedData_dim1",
     "expr": "$.nestedData.dim1"
   }
 ]
 ...
}
</code></pre>
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