docs/topics/impala_live_progress.xml

<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept rev="2.3.0" id="live_progress">

  <title>LIVE_PROGRESS Query Option (<keyword keyref="impala23"/> or higher only)</title>
  <titlealts audience="PDF"><navtitle>LIVE_PROGRESS</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="Performance"/>
      <data name="Category" value="Reports"/>
      <data name="Category" value="impala-shell"/>
      <data name="Category" value="Developers"/>
      <data name="Category" value="Data Analysts"/>
    </metadata>
  </prolog>

  <conbody>

    <p rev="2.3.0"> When the <codeph>LIVE_PROGRESS</codeph> query option is set
      to <codeph>TRUE</codeph>, Impala displays an interactive progress bar
      showing roughly what percentage of processing has been completed for
      queries submitted through the <cmdname>impala-shell</cmdname> command.
      When the query finishes, the progress bar is erased from the
        <cmdname>impala-shell</cmdname> console output. </p>
    <p>Starting in <keyword keyref="impala31"/>, the summary output also
      includes the queuing status consisting of whether the query was queued and
      what was the latest queuing reason.</p>
    <p><b>Type:</b>
      <codeph>Boolean</codeph></p>
    <p><b>Default:</b>
      <codeph>FALSE (0)</codeph></p>

    <p conref="../shared/impala_common.xml#common/command_line_blurb"/>
    <p>
      You can enable this query option within <cmdname>impala-shell</cmdname>
      by starting the shell with the <codeph>--live_progress</codeph>
      command-line option.
      You can still turn this setting off and on again within the shell through the
      <codeph>SET</codeph> command.
    </p>

    <p conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
    <p conref="../shared/impala_common.xml#common/live_reporting_details"/>
    <p>
      For a more detailed way of tracking the progress of an interactive query through
      all phases of processing, see <xref href="impala_live_summary.xml#live_summary"/>.
    </p>

    <p conref="../shared/impala_common.xml#common/restrictions_blurb"/>
    <p>
      Because the percentage complete figure is calculated using the number of
      issued and completed <q>scan ranges</q>, which occur while reading the table
      data, the progress bar might reach 100% before the query is entirely finished.
      For example, the query might do work to perform aggregations after all the
      table data has been read. If many of your queries fall into this category,
      consider using the <codeph>LIVE_SUMMARY</codeph> option instead for
      more granular progress reporting.
    </p>
    <p conref="../shared/impala_common.xml#common/impala_shell_progress_reports_compute_stats_caveat"/>
    <p conref="../shared/impala_common.xml#common/impala_shell_progress_reports_shell_only_caveat"/>

    <p conref="../shared/impala_common.xml#common/added_in_230"/>

    <p conref="../shared/impala_common.xml#common/example_blurb"/>
<codeblock><![CDATA[[localhost:21000] > set live_progress=true;
LIVE_PROGRESS set to true
[localhost:21000] > select count(*) from customer;
+----------+
| count(*) |
+----------+
| 150000   |
+----------+
[localhost:21000] > select count(*) from customer t1 cross join customer t2;
[###################################                                   ] 50%
[######################################################################] 100%

]]>
</codeblock>

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

  </conbody>
</concept>