<xref linkend="mvcc"/>.
  </para>
 </sect1>

 <sect1 id="progress-reporting">
  <title>Progress Reporting</title>

  <para>
   <productname>PostgreSQL</productname> has the ability to report the progress of
   certain commands during command execution.  Currently, the only commands
   which support progress reporting are <command>ANALYZE</command>,
   <command>CLUSTER</command>,
   <command>CREATE INDEX</command>, <command>VACUUM</command>,
   <command>COPY</command>,
   and <xref linkend="protocol-replication-base-backup"/> (i.e., replication
   command that <xref linkend="app-pgbasebackup"/> issues to take
   a base backup).
   This may be expanded in the future.
  </para>

 <sect2 id="analyze-progress-reporting">
  <title>ANALYZE Progress Reporting</title>

  <indexterm>
   <primary>pg_stat_progress_analyze</primary>
  </indexterm>

  <para>
   Whenever <command>ANALYZE</command> is running, the
   <structname>pg_stat_progress_analyze</structname> view will contain a
   row for each backend that is currently running that command.  The tables
   below describe the information that will be reported and provide
   information about how to interpret it.
  </para>

  <table id="pg-stat-progress-analyze-view" xreflabel="pg_stat_progress_analyze">
   <title><structname>pg_stat_progress_analyze</structname> View</title>
   <tgroup cols="1">
    <thead>
     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       Column Type
      </para>
      <para>
       Description
      </para></entry>
     </row>
    </thead>

    <tbody>
     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>pid</structfield> <type>integer</type>
      </para>
      <para>
       Process ID of backend.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>datid</structfield> <type>oid</type>
      </para>
      <para>
       OID of the database to which this backend is connected.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>datname</structfield> <type>name</type>
      </para>
      <para>
       Name of the database to which this backend is connected.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>relid</structfield> <type>oid</type>
      </para>
      <para>
       OID of the table being analyzed.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>phase</structfield> <type>text</type>
      </para>
      <para>
       Current processing phase. See <xref linkend="analyze-phases"/>.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>sample_blks_total</structfield> <type>bigint</type>
      </para>
      <para>
       Total number of heap blocks that will be sampled.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>sample_blks_scanned</structfield> <type>bigint</type>
      </para>
      <para>
       Number of heap blocks scanned.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>ext_stats_total</structfield> <type>bigint</type>
      </para>
      <para>
       Number of extended statistics.
      </para></entry>
     </row>

     <row>
      <entry role="catalog_table_entry"><para role="column_definition">
       <structfield>ext_stats_computed</structfield> <type>bigint</type>
      </para>
      <para>
       Number of extended statistics computed. This counter only advances
       when the phase is <literal>computing extended statistics</literal>.
      </para></entry>