docs/topics/impala_upsert.xml

<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="upsert">

  <title>UPSERT Statement (<keyword keyref="impala28"/> or higher only)</title>
  <titlealts audience="PDF"><navtitle>UPSERT</navtitle></titlealts>
  <prolog>
    <metadata>
      <data name="Category" value="Impala"/>
      <data name="Category" value="SQL"/>
      <data name="Category" value="Kudu"/>
      <data name="Category" value="ETL"/>
      <data name="Category" value="Ingest"/>
      <data name="Category" value="DML"/>
      <data name="Category" value="Developers"/>
      <data name="Category" value="Data Analysts"/>
    </metadata>
  </prolog>

  <conbody>

    <p>
      <indexterm audience="Cloudera">UPSERT statement</indexterm>
      Acts as a combination of the <codeph>INSERT</codeph>
      and <codeph>UPDATE</codeph> statements.
      For each row processed by the <codeph>UPSERT</codeph>
      statement:
      <ul>
        <li>
          <p>
            If another row already exists with the same set of primary key
            values, the other columns are updated to match the values
            from the row being <q>UPSERTed</q>.
          </p>
        </li>
        <li>
          <p>
            If there is not any row with the same set of primary key values,
            the row is created, the same as if the <codeph>INSERT</codeph>
            statement was used.
          </p>
        </li>
      </ul>
    </p>

    <p>
      Although inserting or updating a single row or a small set of rows would be inefficient for tables using HDFS
      data files, Kudu is able to perform this operation efficiently.
      Therefore, this statement only works for Impala tables that use the
      Kudu storage engine.
    </p>

    <p conref="../shared/impala_common.xml#common/syntax_blurb"/>

<codeblock>
</codeblock>

    <p conref="../shared/impala_common.xml#common/dml_blurb"/>

    <p conref="../shared/impala_common.xml#common/usage_notes_blurb"/>

    <p conref="../shared/impala_common.xml#common/sync_ddl_blurb"/>

    <note conref="../shared/impala_common.xml#common/compute_stats_next"/>

    <p conref="../shared/impala_common.xml#common/example_blurb"/>
<codeblock>

</codeblock>

    <p conref="../shared/impala_common.xml#common/related_info"/>

    <p>
      <xref href="impala_kudu.xml#impala_kudu"/>,
      <xref href="impala_insert.xml#insert"/>,
      <xref href="impala_update.xml#update"/>
    </p>

  </conbody>

</concept>