docs/topics/impala_compute_stats_min_sample_size.xml

<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="compute_stats_sample_min_sample_size" rev="2.12.0">
  <title>COMPUTE_STATS_MIN_SAMPLE_SIZE Query Option</title>
  <titlealts audience="PDF">
    <navtitle>COMPUTE_STATS_MIN_SAMPLE_SIZE</navtitle>
  </titlealts>
  <prolog>
    <metadata>
      <data name="Category" value="Impala"/>
      <data name="Category" value="Impala Query Options"/>
      <data name="Category" value="Querying"/>
      <data name="Category" value="Developers"/>
      <data name="Category" value="Data Analysts"/>
    </metadata>
  </prolog>
  <conbody>
    <p>The <codeph>COMPUTE_STATS_MIN_SAMPLE_SIZE</codeph> query option specifies
      the minimum number of bytes that will be scanned in <codeph>COMPUTE STATS
        TABLESAMPLE</codeph>, regardless of the user-supplied sampling percent.
      This query option prevents sampling for very small tables where accurate
      stats can be obtained cheaply without sampling because the minimum sample
      size is required to get meaningful stats.</p>
    <p conref="../shared/impala_common.xml#common/type_integer"/>
    <p><b>Default:</b> 1GB</p>
    <p><b>Added in</b>: <keyword keyref="impala212_full"/></p>
    <p conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
  </conbody>
</concept>