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| <p>This tutorial will demonstrate how to use transform specs to filter and transform input data during ingestion.</p> |
| <p>For this tutorial, we'll assume you've already downloaded Apache Druid as described in |
| the <a href="index.html">single-machine quickstart</a> and have it running on your local machine.</p> |
| <p>It will also be helpful to have finished <a href="/docs/0.17.1/tutorials/tutorial-batch.html">Tutorial: Loading a file</a> and <a href="/docs/0.17.1/tutorials/tutorial-query.html">Tutorial: Querying data</a>.</p> |
| <h2><a class="anchor" aria-hidden="true" id="sample-data"></a><a href="#sample-data" 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>Sample data</h2> |
| <p>We've included sample data for this tutorial at <code>quickstart/tutorial/transform-data.json</code>, reproduced here for convenience:</p> |
| <pre><code class="hljs css language-json">{<span class="hljs-attr">"timestamp"</span>:<span class="hljs-string">"2018-01-01T07:01:35Z"</span>,<span class="hljs-attr">"animal"</span>:<span class="hljs-string">"octopus"</span>, <span class="hljs-attr">"location"</span>:<span class="hljs-number">1</span>, <span class="hljs-attr">"number"</span>:<span class="hljs-number">100</span>} |
| {<span class="hljs-attr">"timestamp"</span>:<span class="hljs-string">"2018-01-01T05:01:35Z"</span>,<span class="hljs-attr">"animal"</span>:<span class="hljs-string">"mongoose"</span>, <span class="hljs-attr">"location"</span>:<span class="hljs-number">2</span>,<span class="hljs-attr">"number"</span>:<span class="hljs-number">200</span>} |
| {<span class="hljs-attr">"timestamp"</span>:<span class="hljs-string">"2018-01-01T06:01:35Z"</span>,<span class="hljs-attr">"animal"</span>:<span class="hljs-string">"snake"</span>, <span class="hljs-attr">"location"</span>:<span class="hljs-number">3</span>, <span class="hljs-attr">"number"</span>:<span class="hljs-number">300</span>} |
| {<span class="hljs-attr">"timestamp"</span>:<span class="hljs-string">"2018-01-01T01:01:35Z"</span>,<span class="hljs-attr">"animal"</span>:<span class="hljs-string">"lion"</span>, <span class="hljs-attr">"location"</span>:<span class="hljs-number">4</span>, <span class="hljs-attr">"number"</span>:<span class="hljs-number">300</span>} |
| </code></pre> |
| <h2><a class="anchor" aria-hidden="true" id="load-data-with-transform-specs"></a><a href="#load-data-with-transform-specs" 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>Load data with transform specs</h2> |
| <p>We will ingest the sample data using the following spec, which demonstrates the use of transform specs:</p> |
| <pre><code class="hljs css language-json">{ |
| <span class="hljs-attr">"type"</span> : <span class="hljs-string">"index_parallel"</span>, |
| <span class="hljs-attr">"spec"</span> : { |
| <span class="hljs-attr">"dataSchema"</span> : { |
| <span class="hljs-attr">"dataSource"</span> : <span class="hljs-string">"transform-tutorial"</span>, |
| <span class="hljs-attr">"timestampSpec"</span>: { |
| <span class="hljs-attr">"column"</span>: <span class="hljs-string">"timestamp"</span>, |
| <span class="hljs-attr">"format"</span>: <span class="hljs-string">"iso"</span> |
| }, |
| <span class="hljs-attr">"dimensionsSpec"</span> : { |
| <span class="hljs-attr">"dimensions"</span> : [ |
| <span class="hljs-string">"animal"</span>, |
| { <span class="hljs-attr">"name"</span>: <span class="hljs-string">"location"</span>, <span class="hljs-attr">"type"</span>: <span class="hljs-string">"long"</span> } |
| ] |
| }, |
| <span class="hljs-attr">"metricsSpec"</span> : [ |
| { <span class="hljs-attr">"type"</span> : <span class="hljs-string">"count"</span>, <span class="hljs-attr">"name"</span> : <span class="hljs-string">"count"</span> }, |
| { <span class="hljs-attr">"type"</span> : <span class="hljs-string">"longSum"</span>, <span class="hljs-attr">"name"</span> : <span class="hljs-string">"number"</span>, <span class="hljs-attr">"fieldName"</span> : <span class="hljs-string">"number"</span> }, |
| { <span class="hljs-attr">"type"</span> : <span class="hljs-string">"longSum"</span>, <span class="hljs-attr">"name"</span> : <span class="hljs-string">"triple-number"</span>, <span class="hljs-attr">"fieldName"</span> : <span class="hljs-string">"triple-number"</span> } |
| ], |
| <span class="hljs-attr">"granularitySpec"</span> : { |
| <span class="hljs-attr">"type"</span> : <span class="hljs-string">"uniform"</span>, |
| <span class="hljs-attr">"segmentGranularity"</span> : <span class="hljs-string">"week"</span>, |
| <span class="hljs-attr">"queryGranularity"</span> : <span class="hljs-string">"minute"</span>, |
| <span class="hljs-attr">"intervals"</span> : [<span class="hljs-string">"2018-01-01/2018-01-03"</span>], |
| <span class="hljs-attr">"rollup"</span> : <span class="hljs-literal">true</span> |
| }, |
| <span class="hljs-attr">"transformSpec"</span>: { |
| <span class="hljs-attr">"transforms"</span>: [ |
| { |
| <span class="hljs-attr">"type"</span>: <span class="hljs-string">"expression"</span>, |
| <span class="hljs-attr">"name"</span>: <span class="hljs-string">"animal"</span>, |
| <span class="hljs-attr">"expression"</span>: <span class="hljs-string">"concat('super-', animal)"</span> |
| }, |
| { |
| <span class="hljs-attr">"type"</span>: <span class="hljs-string">"expression"</span>, |
| <span class="hljs-attr">"name"</span>: <span class="hljs-string">"triple-number"</span>, |
| <span class="hljs-attr">"expression"</span>: <span class="hljs-string">"number * 3"</span> |
| } |
| ], |
| <span class="hljs-attr">"filter"</span>: { |
| <span class="hljs-attr">"type"</span>:<span class="hljs-string">"or"</span>, |
| <span class="hljs-attr">"fields"</span>: [ |
| { <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>, <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"animal"</span>, <span class="hljs-attr">"value"</span>: <span class="hljs-string">"super-mongoose"</span> }, |
| { <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>, <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"triple-number"</span>, <span class="hljs-attr">"value"</span>: <span class="hljs-string">"300"</span> }, |
| { <span class="hljs-attr">"type"</span>: <span class="hljs-string">"selector"</span>, <span class="hljs-attr">"dimension"</span>: <span class="hljs-string">"location"</span>, <span class="hljs-attr">"value"</span>: <span class="hljs-string">"3"</span> } |
| ] |
| } |
| } |
| }, |
| <span class="hljs-attr">"ioConfig"</span> : { |
| <span class="hljs-attr">"type"</span> : <span class="hljs-string">"index_parallel"</span>, |
| <span class="hljs-attr">"inputSource"</span> : { |
| <span class="hljs-attr">"type"</span> : <span class="hljs-string">"local"</span>, |
| <span class="hljs-attr">"baseDir"</span> : <span class="hljs-string">"quickstart/tutorial"</span>, |
| <span class="hljs-attr">"filter"</span> : <span class="hljs-string">"transform-data.json"</span> |
| }, |
| <span class="hljs-attr">"inputFormat"</span> : { |
| <span class="hljs-attr">"type"</span> :<span class="hljs-string">"json"</span> |
| }, |
| <span class="hljs-attr">"appendToExisting"</span> : <span class="hljs-literal">false</span> |
| }, |
| <span class="hljs-attr">"tuningConfig"</span> : { |
| <span class="hljs-attr">"type"</span> : <span class="hljs-string">"index_parallel"</span>, |
| <span class="hljs-attr">"maxRowsPerSegment"</span> : <span class="hljs-number">5000000</span>, |
| <span class="hljs-attr">"maxRowsInMemory"</span> : <span class="hljs-number">25000</span> |
| } |
| } |
| } |
| </code></pre> |
| <p>In the transform spec, we have two expression transforms:</p> |
| <ul> |
| <li><code>super-animal</code>: prepends "super-" to the values in the <code>animal</code> column. This will override the <code>animal</code> column with the transformed version, since the transform's name is <code>animal</code>.</li> |
| <li><code>triple-number</code>: multiplies the <code>number</code> column by 3. This will create a new <code>triple-number</code> column. Note that we are ingesting both the original and the transformed column.</li> |
| </ul> |
| <p>Additionally, we have an OR filter with three clauses:</p> |
| <ul> |
| <li><code>super-animal</code> values that match "super-mongoose"</li> |
| <li><code>triple-number</code> values that match 300</li> |
| <li><code>location</code> values that match 3</li> |
| </ul> |
| <p>This filter selects the first 3 rows, and it will exclude the final "lion" row in the input data. Note that the filter is applied after the transformation.</p> |
| <p>Let's submit this task now, which has been included at <code>quickstart/tutorial/transform-index.json</code>:</p> |
| <pre><code class="hljs css language-bash">bin/post-index-task --file quickstart/tutorial/transform-index.json --url http://localhost:8081 |
| </code></pre> |
| <h2><a class="anchor" aria-hidden="true" id="query-the-transformed-data"></a><a href="#query-the-transformed-data" 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>Query the transformed data</h2> |
| <p>Let's run <code>bin/dsql</code> and issue a <code>select * from "transform-tutorial";</code> query to see what was ingested:</p> |
| <pre><code class="hljs css language-bash">dsql> select * from <span class="hljs-string">"transform-tutorial"</span>; |
| ┌──────────────────────────┬────────────────┬───────┬──────────┬────────┬───────────────┐ |
| │ __time │ animal │ count │ location │ number │ triple-number │ |
| ├──────────────────────────┼────────────────┼───────┼──────────┼────────┼───────────────┤ |
| │ 2018-01-01T05:01:00.000Z │ super-mongoose │ 1 │ 2 │ 200 │ 600 │ |
| │ 2018-01-01T06:01:00.000Z │ super-snake │ 1 │ 3 │ 300 │ 900 │ |
| │ 2018-01-01T07:01:00.000Z │ super-octopus │ 1 │ 1 │ 100 │ 300 │ |
| └──────────────────────────┴────────────────┴───────┴──────────┴────────┴───────────────┘ |
| Retrieved 3 rows <span class="hljs-keyword">in</span> 0.03s. |
| </code></pre> |
| <p>The "lion" row has been discarded, the <code>animal</code> column has been transformed, and we have both the original and transformed <code>number</code> column.</p> |
| </span></div></article></div><div class="docs-prevnext"><a class="docs-prev button" href="/docs/0.17.1/tutorials/tutorial-ingestion-spec.html"><span class="arrow-prev">← </span><span>Writing an ingestion spec</span></a><a class="docs-next button" href="/docs/0.17.1/tutorials/tutorial-kerberos-hadoop.html"><span>Kerberized HDFS deep storage</span><span class="arrow-next"> →</span></a></div></div></div><nav class="onPageNav"><ul class="toc-headings"><li><a href="#sample-data">Sample data</a></li><li><a href="#load-data-with-transform-specs">Load data with transform specs</a></li><li><a href="#query-the-transformed-data">Query the transformed data</a></li></ul></nav></div><footer class="nav-footer druid-footer" id="footer"><div class="container"><div class="text-center"><p><a href="/technology">Technology</a> · <a href="/use-cases">Use Cases</a> · <a href="/druid-powered">Powered by Druid</a> · <a href="/docs/0.17.1/latest">Docs</a> · <a href="/community/">Community</a> · <a href="/downloads.html">Download</a> · <a href="/faq">FAQ</a></p></div><div class="text-center"><a title="Join the user group" href="https://groups.google.com/forum/#!forum/druid-user" target="_blank"><span class="fa fa-comments"></span></a> · <a title="Follow Druid" href="https://twitter.com/druidio" target="_blank"><span class="fab fa-twitter"></span></a> · <a title="Download via Apache" href="https://www.apache.org/dyn/closer.cgi?path=/incubator/druid/{{ site.druid_versions[0].versions[0].version }}/apache-druid-{{ site.druid_versions[0].versions[0].version }}-bin.tar.gz" target="_blank"><span class="fas fa-feather"></span></a> · <a title="GitHub" href="https://github.com/apache/druid" target="_blank"><span class="fab fa-github"></span></a></div><div class="text-center license">Copyright © 2019 <a href="https://www.apache.org/" target="_blank">Apache Software Foundation</a>.<br/>Except where otherwise noted, licensed under <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA 4.0</a>.<br/>Apache Druid, Druid, and the Druid logo are either registered trademarks or trademarks of The Apache Software Foundation in the United States and other countries.</div></div></footer></div><script type="text/javascript" src="https://cdn.jsdelivr.net/docsearch.js/1/docsearch.min.js"></script><script> |
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