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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>28.4. Progress Reporting</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="monitoring-locks.html" title="28.3. Viewing Locks" /><link rel="next" href="dynamic-trace.html" title="28.5. Dynamic Tracing" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">28.4. Progress Reporting</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="monitoring-locks.html" title="28.3. Viewing Locks">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="monitoring.html" title="Chapter 28. Monitoring Database Activity">Up</a></td><th width="60%" align="center">Chapter 28. Monitoring Database Activity</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="dynamic-trace.html" title="28.5. Dynamic Tracing">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="PROGRESS-REPORTING"><div class="titlepage"><div><div><h2 class="title" style="clear: both">28.4. Progress Reporting</h2></div></div></div><div class="toc"><dl class="toc"><dt><span class="sect2"><a href="progress-reporting.html#VACUUM-PROGRESS-REPORTING">28.4.1. VACUUM Progress Reporting</a></span></dt></dl></div><p>
<span class="productname">PostgreSQL</span> has the ability to report the progress of
certain commands during command execution. Currently, the only command
which supports progress reporting is <code class="command">VACUUM</code>. This may be
expanded in the future.
</p><div class="sect2" id="VACUUM-PROGRESS-REPORTING"><div class="titlepage"><div><div><h3 class="title">28.4.1. VACUUM Progress Reporting</h3></div></div></div><p>
Whenever <code class="command">VACUUM</code> is running, the
<code class="structname">pg_stat_progress_vacuum</code> view will contain
one row for each backend (including autovacuum worker processes) that is
currently vacuuming. The tables below describe the information
that will be reported and provide information about how to interpret it.
Progress reporting is not currently supported for <code class="command">VACUUM FULL</code>
and backends running <code class="command">VACUUM FULL</code> will not be listed in this
view.
</p><div class="table" id="PG-STAT-PROGRESS-VACUUM-VIEW"><p class="title"><strong>Table 28.21. <code class="structname">pg_stat_progress_vacuum</code> View</strong></p><div class="table-contents"><table class="table" summary="pg_stat_progress_vacuum View" border="1"><colgroup><col /><col /><col /></colgroup><thead><tr><th>Column</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><code class="structfield">pid</code></td><td><code class="type">integer</code></td><td>Process ID of backend.</td></tr><tr><td><code class="structfield">datid</code></td><td><code class="type">oid</code></td><td>OID of the database to which this backend is connected.</td></tr><tr><td><code class="structfield">datname</code></td><td><code class="type">name</code></td><td>Name of the database to which this backend is connected.</td></tr><tr><td><code class="structfield">relid</code></td><td><code class="type">oid</code></td><td>OID of the table being vacuumed.</td></tr><tr><td><code class="structfield">phase</code></td><td><code class="type">text</code></td><td>
Current processing phase of vacuum. See <a class="xref" href="progress-reporting.html#VACUUM-PHASES" title="Table 28.22. VACUUM phases">Table 28.22</a>.
</td></tr><tr><td><code class="structfield">heap_blks_total</code></td><td><code class="type">bigint</code></td><td>
Total number of heap blocks in the table. This number is reported
as of the beginning of the scan; blocks added later will not be (and
need not be) visited by this <code class="command">VACUUM</code>.
</td></tr><tr><td><code class="structfield">heap_blks_scanned</code></td><td><code class="type">bigint</code></td><td>
Number of heap blocks scanned. Because the
<a class="link" href="storage-vm.html" title="68.4. Visibility Map">visibility map</a> is used to optimize scans,
some blocks will be skipped without inspection; skipped blocks are
included in this total, so that this number will eventually become
equal to <code class="structfield">heap_blks_total</code> when the vacuum is complete.
This counter only advances when the phase is <code class="literal">scanning heap</code>.
</td></tr><tr><td><code class="structfield">heap_blks_vacuumed</code></td><td><code class="type">bigint</code></td><td>
Number of heap blocks vacuumed. Unless the table has no indexes, this
counter only advances when the phase is <code class="literal">vacuuming heap</code>.
Blocks that contain no dead tuples are skipped, so the counter may
sometimes skip forward in large increments.
</td></tr><tr><td><code class="structfield">index_vacuum_count</code></td><td><code class="type">bigint</code></td><td>
Number of completed index vacuum cycles.
</td></tr><tr><td><code class="structfield">max_dead_tuples</code></td><td><code class="type">bigint</code></td><td>
Number of dead tuples that we can store before needing to perform
an index vacuum cycle, based on
<a class="xref" href="runtime-config-resource.html#GUC-MAINTENANCE-WORK-MEM">maintenance_work_mem</a>.
</td></tr><tr><td><code class="structfield">num_dead_tuples</code></td><td><code class="type">bigint</code></td><td>
Number of dead tuples collected since the last index vacuum cycle.
</td></tr></tbody></table></div></div><br class="table-break" /><div class="table" id="VACUUM-PHASES"><p class="title"><strong>Table 28.22. VACUUM phases</strong></p><div class="table-contents"><table class="table" summary="VACUUM phases" border="1"><colgroup><col /><col /></colgroup><thead><tr><th>Phase</th><th>Description</th></tr></thead><tbody><tr><td><code class="literal">initializing</code></td><td>
<code class="command">VACUUM</code> is preparing to begin scanning the heap. This
phase is expected to be very brief.
</td></tr><tr><td><code class="literal">scanning heap</code></td><td>
<code class="command">VACUUM</code> is currently scanning the heap. It will prune and
defragment each page if required, and possibly perform freezing
activity. The <code class="structfield">heap_blks_scanned</code> column can be used
to monitor the progress of the scan.
</td></tr><tr><td><code class="literal">vacuuming indexes</code></td><td>
<code class="command">VACUUM</code> is currently vacuuming the indexes. If a table has
any indexes, this will happen at least once per vacuum, after the heap
has been completely scanned. It may happen multiple times per vacuum
if <a class="xref" href="runtime-config-resource.html#GUC-MAINTENANCE-WORK-MEM">maintenance_work_mem</a> is insufficient to
store the number of dead tuples found.
</td></tr><tr><td><code class="literal">vacuuming heap</code></td><td>
<code class="command">VACUUM</code> is currently vacuuming the heap. Vacuuming the heap
is distinct from scanning the heap, and occurs after each instance of
vacuuming indexes. If <code class="structfield">heap_blks_scanned</code> is less than
<code class="structfield">heap_blks_total</code>, the system will return to scanning
the heap after this phase is completed; otherwise, it will begin
cleaning up indexes after this phase is completed.
</td></tr><tr><td><code class="literal">cleaning up indexes</code></td><td>
<code class="command">VACUUM</code> is currently cleaning up indexes. This occurs after
the heap has been completely scanned and all vacuuming of the indexes
and the heap has been completed.
</td></tr><tr><td><code class="literal">truncating heap</code></td><td>
<code class="command">VACUUM</code> is currently truncating the heap so as to return
empty pages at the end of the relation to the operating system. This
occurs after cleaning up indexes.
</td></tr><tr><td><code class="literal">performing final cleanup</code></td><td>
<code class="command">VACUUM</code> is performing final cleanup. During this phase,
<code class="command">VACUUM</code> will vacuum the free space map, update statistics
in <code class="literal">pg_class</code>, and report statistics to the statistics
collector. When this phase is completed, <code class="command">VACUUM</code> will end.
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