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1<?xml version="1.0" encoding="UTF-8" standalone="no"?>2<!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>pg_upgrade</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="pgtesttiming.html" title="pg_test_timing" /><link rel="next" href="pgwaldump.html" title="pg_waldump" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center"><span class="application">pg_upgrade</span></th></tr><tr><td width="10%" align="left"><a accesskey="p" href="pgtesttiming.html" title="pg_test_timing">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="reference-server.html" title="PostgreSQL Server Applications">Up</a></td><th width="60%" align="center">PostgreSQL Server Applications</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="pgwaldump.html" title="pg_waldump">Next</a></td></tr></table><hr /></div><div class="refentry" id="PGUPGRADE"><div class="titlepage"></div><a id="id-1.9.5.12.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle"><span class="application">pg_upgrade</span></span></h2><p>pg_upgrade — upgrade a <span class="productname">PostgreSQL</span> server instance</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="cmdsynopsis"><p id="id-1.9.5.12.4.1"><code class="command">pg_upgrade</code>  <code class="option">-b</code>   <em class="replaceable"><code>oldbindir</code></em>  [<code class="option">-B</code> <em class="replaceable"><code>newbindir</code></em>]  <code class="option">-d</code>   <em class="replaceable"><code>oldconfigdir</code></em>   <code class="option">-D</code>   <em class="replaceable"><code>newconfigdir</code></em>  [<em class="replaceable"><code>option</code></em>...]</p></div></div><div class="refsect1" id="id-1.9.5.12.5"><h2>Description</h2><p>3  <span class="application">pg_upgrade</span> (formerly called <span class="application">pg_migrator</span>) allows data4  stored in <span class="productname">PostgreSQL</span> data files to be upgraded to a later <span class="productname">PostgreSQL</span>5  major version without the data dump/restore typically required for6  major version upgrades, e.g., from 12.14 to 13.10 or from 14.9 to 15.5.7  It is not required for minor version upgrades, e.g., from 12.7 to 12.88  or from 14.1 to 14.5.9 </p><p>10  Major PostgreSQL releases regularly add new features that often11  change the layout of the system tables, but the internal data storage12  format rarely changes.  <span class="application">pg_upgrade</span> uses this fact13  to perform rapid upgrades by creating new system tables and simply14  reusing the old user data files.  If a future major release ever15  changes the data storage format in a way that makes the old data16  format unreadable, <span class="application">pg_upgrade</span> will not be usable17  for such upgrades.  (The community will attempt to avoid such18  situations.)19 </p><p>20  <span class="application">pg_upgrade</span> does its best to21  make sure the old and new clusters are binary-compatible, e.g.,  by22  checking for compatible compile-time settings, including 32/64-bit23  binaries.  It is important that24  any external modules are also binary compatible, though this cannot25  be checked by <span class="application">pg_upgrade</span>.26 </p><p>27   pg_upgrade supports upgrades from 9.2.X and later to the current28   major release of <span class="productname">PostgreSQL</span>, including snapshot and beta releases.29  </p></div><div class="refsect1" id="id-1.9.5.12.6"><h2>Options</h2><p>30    <span class="application">pg_upgrade</span> accepts the following command-line arguments:31 32    </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="option">-b</code> <em class="replaceable"><code>bindir</code></em><br /></span><span class="term"><code class="option">--old-bindir=</code><em class="replaceable"><code>bindir</code></em></span></dt><dd><p>the old PostgreSQL executable directory;33      environment variable <code class="envar">PGBINOLD</code></p></dd><dt><span class="term"><code class="option">-B</code> <em class="replaceable"><code>bindir</code></em><br /></span><span class="term"><code class="option">--new-bindir=</code><em class="replaceable"><code>bindir</code></em></span></dt><dd><p>the new PostgreSQL executable directory;34      default is the directory where <span class="application">pg_upgrade</span> resides;35      environment variable <code class="envar">PGBINNEW</code></p></dd><dt><span class="term"><code class="option">-c</code><br /></span><span class="term"><code class="option">--check</code></span></dt><dd><p>check clusters only, don't change any data</p></dd><dt><span class="term"><code class="option">-d</code> <em class="replaceable"><code>configdir</code></em><br /></span><span class="term"><code class="option">--old-datadir=</code><em class="replaceable"><code>configdir</code></em></span></dt><dd><p>the old database cluster configuration directory; environment36      variable <code class="envar">PGDATAOLD</code></p></dd><dt><span class="term"><code class="option">-D</code> <em class="replaceable"><code>configdir</code></em><br /></span><span class="term"><code class="option">--new-datadir=</code><em class="replaceable"><code>configdir</code></em></span></dt><dd><p>the new database cluster configuration directory; environment37      variable <code class="envar">PGDATANEW</code></p></dd><dt><span class="term"><code class="option">-j <em class="replaceable"><code>njobs</code></em></code><br /></span><span class="term"><code class="option">--jobs=<em class="replaceable"><code>njobs</code></em></code></span></dt><dd><p>number of simultaneous processes or threads to use38      </p></dd><dt><span class="term"><code class="option">-k</code><br /></span><span class="term"><code class="option">--link</code></span></dt><dd><p>use hard links instead of copying files to the new39      cluster</p></dd><dt><span class="term"><code class="option">-N</code><br /></span><span class="term"><code class="option">--no-sync</code></span></dt><dd><p>40        By default, <code class="command">pg_upgrade</code> will wait for all files41        of the upgraded cluster to be written safely to disk.  This option42        causes <code class="command">pg_upgrade</code> to return without waiting, which43        is faster, but means that a subsequent operating system crash can leave44        the data directory corrupt.  Generally, this option is45        useful for testing but should not be used on a production46        installation.47       </p></dd><dt><span class="term"><code class="option">-o</code> <em class="replaceable"><code>options</code></em><br /></span><span class="term"><code class="option">--old-options</code> <em class="replaceable"><code>options</code></em></span></dt><dd><p>options to be passed directly to the48      old <code class="command">postgres</code> command;  multiple49      option invocations are appended</p></dd><dt><span class="term"><code class="option">-O</code> <em class="replaceable"><code>options</code></em><br /></span><span class="term"><code class="option">--new-options</code> <em class="replaceable"><code>options</code></em></span></dt><dd><p>options to be passed directly to the50      new <code class="command">postgres</code> command;  multiple51      option invocations are appended</p></dd><dt><span class="term"><code class="option">-p</code> <em class="replaceable"><code>port</code></em><br /></span><span class="term"><code class="option">--old-port=</code><em class="replaceable"><code>port</code></em></span></dt><dd><p>the old cluster port number; environment52      variable <code class="envar">PGPORTOLD</code></p></dd><dt><span class="term"><code class="option">-P</code> <em class="replaceable"><code>port</code></em><br /></span><span class="term"><code class="option">--new-port=</code><em class="replaceable"><code>port</code></em></span></dt><dd><p>the new cluster port number; environment53      variable <code class="envar">PGPORTNEW</code></p></dd><dt><span class="term"><code class="option">-r</code><br /></span><span class="term"><code class="option">--retain</code></span></dt><dd><p>retain SQL and log files even after successful completion54      </p></dd><dt><span class="term"><code class="option">-s</code> <em class="replaceable"><code>dir</code></em><br /></span><span class="term"><code class="option">--socketdir=</code><em class="replaceable"><code>dir</code></em></span></dt><dd><p>directory to use for postmaster sockets during upgrade;55      default is current working directory; environment56      variable <code class="envar">PGSOCKETDIR</code></p></dd><dt><span class="term"><code class="option">-U</code> <em class="replaceable"><code>username</code></em><br /></span><span class="term"><code class="option">--username=</code><em class="replaceable"><code>username</code></em></span></dt><dd><p>cluster's install user name; environment57      variable <code class="envar">PGUSER</code></p></dd><dt><span class="term"><code class="option">-v</code><br /></span><span class="term"><code class="option">--verbose</code></span></dt><dd><p>enable verbose internal logging</p></dd><dt><span class="term"><code class="option">-V</code><br /></span><span class="term"><code class="option">--version</code></span></dt><dd><p>display version information, then exit</p></dd><dt><span class="term"><code class="option">--clone</code></span></dt><dd><p>58        Use efficient file cloning (also known as <span class="quote">“<span class="quote">reflinks</span>”</span> on59        some systems) instead of copying files to the new cluster.  This can60        result in near-instantaneous copying of the data files, giving the61        speed advantages of <code class="option">-k</code>/<code class="option">--link</code> while62        leaving the old cluster untouched.63       </p><p>64        File cloning is only supported on some operating systems and file65        systems.  If it is selected but not supported, the66        <span class="application">pg_upgrade</span> run will error.  At present, it67        is supported on Linux (kernel 4.5 or later) with Btrfs and XFS (on68        file systems created with reflink support), and on macOS with APFS.69       </p></dd><dt><span class="term"><code class="option">--copy</code></span></dt><dd><p>70        Copy files to the new cluster.  This is the default.  (See also71        <code class="option">--link</code> and <code class="option">--clone</code>.)72       </p></dd><dt><span class="term"><code class="option">-?</code><br /></span><span class="term"><code class="option">--help</code></span></dt><dd><p>show help, then exit</p></dd></dl></div><p>73   </p></div><div class="refsect1" id="id-1.9.5.12.7"><h2>Usage</h2><p>74   These are the steps to perform an upgrade75   with <span class="application">pg_upgrade</span>:76  </p><div class="procedure"><ol class="procedure" type="1"><li class="step"><p class="title"><strong>Optionally move the old cluster</strong></p><p>77     If you are using a version-specific installation directory, e.g.,78     <code class="filename">/opt/PostgreSQL/16</code>, you do not need to move the old cluster. The79     graphical installers all use version-specific installation directories.80    </p><p>81     If your installation directory is not version-specific, e.g.,82     <code class="filename">/usr/local/pgsql</code>, it is necessary to move the current PostgreSQL install83     directory so it does not interfere with the new <span class="productname">PostgreSQL</span> installation.84     Once the current <span class="productname">PostgreSQL</span> server is shut down, it is safe to rename the85     PostgreSQL installation directory; assuming the old directory is86     <code class="filename">/usr/local/pgsql</code>, you can do:87 88</p><pre class="programlisting">89mv /usr/local/pgsql /usr/local/pgsql.old90</pre><p>91     to rename the directory.92    </p></li><li class="step"><p class="title"><strong>For source installs, build the new version</strong></p><p>93     Build the new PostgreSQL source with <code class="command">configure</code> flags that are compatible94     with the old cluster. <span class="application">pg_upgrade</span> will check <code class="command">pg_controldata</code> to make95     sure all settings are compatible before starting the upgrade.96    </p></li><li class="step"><p class="title"><strong>Install the new PostgreSQL binaries</strong></p><p>97     Install the new server's binaries and support98     files.  <span class="application">pg_upgrade</span> is included in a default installation.99    </p><p>100     For source installs, if you wish to install the new server in a custom101     location, use the <code class="literal">prefix</code> variable:102 103</p><pre class="programlisting">104make prefix=/usr/local/pgsql.new install105</pre></li><li class="step"><p class="title"><strong>Initialize the new PostgreSQL cluster</strong></p><p>106     Initialize the new cluster using <code class="command">initdb</code>.107     Again, use compatible <code class="command">initdb</code>108     flags that match the old cluster. Many109     prebuilt installers do this step automatically. There is no need to110     start the new cluster.111    </p></li><li class="step"><p class="title"><strong>Install extension shared object files</strong></p><p>112     Many extensions and custom modules, whether from113     <code class="filename">contrib</code> or another source, use shared object114     files (or DLLs), e.g., <code class="filename">pgcrypto.so</code>.  If the old115     cluster used these, shared object files matching the new server binary116     must be installed in the new cluster, usually via operating system117     commands.  Do not load the schema definitions, e.g., <code class="command">CREATE118     EXTENSION pgcrypto</code>, because these will be duplicated from119     the old cluster.  If extension updates are available,120     <span class="application">pg_upgrade</span> will report this and create121     a script that can be run later to update them.122    </p></li><li class="step"><p class="title"><strong>Copy custom full-text search files</strong></p><p>123     Copy any custom full text search files (dictionary, synonym,124     thesaurus, stop words) from the old to the new cluster.125    </p></li><li class="step"><p class="title"><strong>Adjust authentication</strong></p><p>126     <code class="command">pg_upgrade</code> will connect to the old and new servers several127     times, so you might want to set authentication to <code class="literal">peer</code>128     in <code class="filename">pg_hba.conf</code> or use a <code class="filename">~/.pgpass</code> file129     (see <a class="xref" href="libpq-pgpass.html" title="34.16. The Password File">Section 34.16</a>).130    </p></li><li class="step"><p class="title"><strong>Stop both servers</strong></p><p>131     Make sure both database servers are stopped using, on Unix, e.g.:132 133</p><pre class="programlisting">134pg_ctl -D /opt/PostgreSQL/12 stop135pg_ctl -D /opt/PostgreSQL/16 stop136</pre><p>137 138     or on Windows, using the proper service names:139 140</p><pre class="programlisting">141NET STOP postgresql-12142NET STOP postgresql-16143</pre><p>144    </p><p>145     Streaming replication and log-shipping standby servers must be146     running during this shutdown so they receive all changes.147    </p></li><li class="step"><p class="title"><strong>Prepare for standby server upgrades</strong></p><p>148     If you are upgrading standby servers using methods outlined in section <a class="xref" href="pgupgrade.html#PGUPGRADE-STEP-REPLICAS" title="Upgrade streaming replication and log-shipping standby servers">Step 11</a>, verify that the old standby149     servers are caught up by running <span class="application">pg_controldata</span>150     against the old primary and standby clusters.  Verify that the151     <span class="quote">“<span class="quote">Latest checkpoint location</span>”</span> values match in all clusters.152     Also, make sure <code class="varname">wal_level</code> is not set to153     <code class="literal">minimal</code> in the <code class="filename">postgresql.conf</code> file on the154     new primary cluster.155    </p></li><li class="step"><p class="title"><strong>Run <span class="application">pg_upgrade</span></strong></p><p>156     Always run the <span class="application">pg_upgrade</span> binary of the new server, not the old one.157     <span class="application">pg_upgrade</span> requires the specification of the old and new cluster's158     data and executable (<code class="filename">bin</code>) directories. You can also specify159     user and port values, and whether you want the data files linked or cloned160     instead of the default copy behavior.161    </p><p>162     If you use link mode, the upgrade will be much faster (no file163     copying) and use less disk space, but you will not be able to access164     your old cluster165     once you start the new cluster after the upgrade.  Link mode also166     requires that the old and new cluster data directories be in the167     same file system.  (Tablespaces and <code class="filename">pg_wal</code> can be on168     different file systems.)169     Clone mode provides the same speed and disk space advantages but170     does not cause the old cluster to be unusable once the new cluster171     is started.  Clone mode also requires that the old and new data172     directories be in the same file system.  This mode is only available173     on certain operating systems and file systems.174    </p><p>175     The <code class="option">--jobs</code> option allows multiple CPU cores to be used176     for copying/linking of files and to dump and restore database schemas177     in parallel;  a good place to start is the maximum of the number of178     CPU cores and tablespaces.  This option can dramatically reduce the179     time to upgrade a multi-database server running on a multiprocessor180     machine.181    </p><p>182     For Windows users, you must be logged into an administrative account, and183     then start a shell as the <code class="literal">postgres</code> user and set the proper path:184 185</p><pre class="programlisting">186RUNAS /USER:postgres "CMD.EXE"187SET PATH=%PATH%;C:\Program Files\PostgreSQL\16\bin;188</pre><p>189 190     and then run <span class="application">pg_upgrade</span> with quoted directories, e.g.:191 192</p><pre class="programlisting">193pg_upgrade.exe194        --old-datadir "C:/Program Files/PostgreSQL/12/data"195        --new-datadir "C:/Program Files/PostgreSQL/16/data"196        --old-bindir "C:/Program Files/PostgreSQL/12/bin"197        --new-bindir "C:/Program Files/PostgreSQL/16/bin"198</pre><p>199 200     Once started, <code class="command">pg_upgrade</code> will verify the two clusters are compatible201     and then do the upgrade. You can use <code class="command">pg_upgrade --check</code>202     to perform only the checks, even if the old server is still203     running. <code class="command">pg_upgrade --check</code> will also outline any204     manual adjustments you will need to make after the upgrade.  If you205     are going to be using link or clone mode, you should use the option206     <code class="option">--link</code> or <code class="option">--clone</code> with207     <code class="option">--check</code> to enable mode-specific checks.208     <code class="command">pg_upgrade</code> requires write permission in the current directory.209    </p><p>210     Obviously, no one should be accessing the clusters during the211     upgrade.  <span class="application">pg_upgrade</span> defaults to running servers212     on port 50432 to avoid unintended client connections.213     You can use the same port number for both clusters when doing an214     upgrade because the old and new clusters will not be running at the215     same time.  However, when checking an old running server, the old216     and new port numbers must be different.217    </p><p>218     If an error occurs while restoring the database schema, <code class="command">pg_upgrade</code> will219     exit and you will have to revert to the old cluster as outlined in <a class="xref" href="pgupgrade.html#PGUPGRADE-STEP-REVERT" title="Reverting to old cluster">Step 17</a>220     below. To try <code class="command">pg_upgrade</code> again, you will need to modify the old221     cluster so the pg_upgrade schema restore succeeds. If the problem is a222     <code class="filename">contrib</code> module, you might need to uninstall the <code class="filename">contrib</code> module from223     the old cluster and install it in the new cluster after the upgrade,224     assuming the module is not being used to store user data.225    </p></li><li class="step" id="PGUPGRADE-STEP-REPLICAS"><p class="title"><strong>Upgrade streaming replication and log-shipping standby servers</strong></p><p>226     If you used link mode and have Streaming Replication (see <a class="xref" href="warm-standby.html#STREAMING-REPLICATION" title="27.2.5. Streaming Replication">Section 27.2.5</a>) or Log-Shipping (see <a class="xref" href="warm-standby.html" title="27.2. Log-Shipping Standby Servers">Section 27.2</a>) standby servers, you can follow these steps to227     quickly upgrade them.  You will not be running <span class="application">pg_upgrade</span> on228     the standby servers, but rather <span class="application">rsync</span> on the primary.229     Do not start any servers yet.230    </p><p>231     If you did <span class="emphasis"><em>not</em></span> use link mode, do not have or do not232     want to use <span class="application">rsync</span>, or want an easier solution, skip233     the instructions in this section and simply recreate the standby234     servers once <span class="application">pg_upgrade</span> completes and the new primary235     is running.236    </p><div class="procedure"><ol class="procedure" type="1"><li class="step"><p class="title"><strong>Install the new PostgreSQL binaries on standby servers</strong></p><p>237       Make sure the new binaries and support files are installed on all238       standby servers.239      </p></li><li class="step"><p class="title"><strong>Make sure the new standby data directories do <span class="emphasis"><em>not</em></span> exist</strong></p><p>240       Make sure the new standby data directories do <span class="emphasis"><em>not</em></span>241       exist or are empty.  If <span class="application">initdb</span> was run, delete242       the standby servers' new data directories.243      </p></li><li class="step"><p class="title"><strong>Install extension shared object files</strong></p><p>244       Install the same extension shared object files on the new standbys245       that you installed in the new primary cluster.246      </p></li><li class="step"><p class="title"><strong>Stop standby servers</strong></p><p>247       If the standby servers are still running, stop them now using the248       above instructions.249      </p></li><li class="step"><p class="title"><strong>Save configuration files</strong></p><p>250       Save any configuration files from the old standbys' configuration251       directories you need to keep, e.g.,  <code class="filename">postgresql.conf</code>252       (and any files included by it), <code class="filename">postgresql.auto.conf</code>,253       <code class="literal">pg_hba.conf</code>, because these will be overwritten254       or removed in the next step.255      </p></li><li class="step"><p class="title"><strong>Run <span class="application">rsync</span></strong></p><p>256       When using link mode, standby servers can be quickly upgraded using257       <span class="application">rsync</span>.  To accomplish this, from a directory on258       the primary server that is above the old and new database cluster259       directories, run this on the <span class="emphasis"><em>primary</em></span> for each standby260       server:261 262</p><pre class="programlisting">263rsync --archive --delete --hard-links --size-only --no-inc-recursive old_cluster new_cluster remote_dir264</pre><p>265 266       where <code class="option">old_cluster</code> and <code class="option">new_cluster</code> are relative267       to the current directory on the primary, and <code class="option">remote_dir</code>268       is <span class="emphasis"><em>above</em></span> the old and new cluster directories269       on the standby.  The directory structure under the specified270       directories on the primary and standbys must match.  Consult the271       <span class="application">rsync</span> manual page for details on specifying the272       remote directory, e.g.,273 274</p><pre class="programlisting">275rsync --archive --delete --hard-links --size-only --no-inc-recursive /opt/PostgreSQL/12 \276      /opt/PostgreSQL/16 standby.example.com:/opt/PostgreSQL277</pre><p>278 279       You can verify what the command will do using280       <span class="application">rsync</span>'s <code class="option">--dry-run</code> option.  While281       <span class="application">rsync</span> must be run on the primary for at least one282       standby, it is possible to run <span class="application">rsync</span> on an upgraded283       standby to upgrade other standbys, as long as the upgraded standby284       has not been started.285      </p><p>286       What this does is to record the links created by287       <span class="application">pg_upgrade</span>'s link mode that connect files in the288       old and new clusters on the primary server.  It then finds matching289       files in the standby's old cluster and creates links for them in the290       standby's new cluster.  Files that were not linked on the primary291       are copied from the primary to the standby.  (They are usually292       small.)  This provides rapid standby upgrades.  Unfortunately,293       <span class="application">rsync</span> needlessly copies files associated with294       temporary and unlogged tables because these files don't normally295       exist on standby servers.296      </p><p>297       If you have tablespaces, you will need to run a similar298       <span class="application">rsync</span> command for each tablespace directory, e.g.:299 300</p><pre class="programlisting">301rsync --archive --delete --hard-links --size-only --no-inc-recursive /vol1/pg_tblsp/PG_12_201909212 \302      /vol1/pg_tblsp/PG_16_202307071 standby.example.com:/vol1/pg_tblsp303</pre><p>304 305       If you have relocated <code class="filename">pg_wal</code> outside the data306       directories, <span class="application">rsync</span> must be run on those directories307       too.308      </p></li><li class="step"><p class="title"><strong>Configure streaming replication and log-shipping standby servers</strong></p><p>309       Configure the servers for log shipping.  (You do not need to run310       <code class="function">pg_backup_start()</code> and <code class="function">pg_backup_stop()</code>311       or take a file system backup as the standbys are still synchronized312       with the primary.)  Replication slots are not copied and must313       be recreated.314      </p></li></ol></div></li><li class="step"><p class="title"><strong>Restore <code class="filename">pg_hba.conf</code></strong></p><p>315     If you modified <code class="filename">pg_hba.conf</code>, restore its original settings.316     It might also be necessary to adjust other configuration files in the new317     cluster to match the old cluster, e.g., <code class="filename">postgresql.conf</code>318     (and any files included by it), <code class="filename">postgresql.auto.conf</code>.319    </p></li><li class="step"><p class="title"><strong>Start the new server</strong></p><p>320     The new server can now be safely started, and then any321     <span class="application">rsync</span>'ed standby servers.322    </p></li><li class="step"><p class="title"><strong>Post-upgrade processing</strong></p><p>323     If any post-upgrade processing is required, pg_upgrade will issue324     warnings as it completes. It will also generate script files that must325     be run by the administrator. The script files will connect to each326     database that needs post-upgrade processing. Each script should be327     run using:328 329</p><pre class="programlisting">330psql --username=postgres --file=script.sql postgres331</pre><p>332 333     The scripts can be run in any order and can be deleted once they have334     been run.335    </p><div class="caution"><h3 class="title">Caution</h3><p>336     In general it is unsafe to access tables referenced in rebuild scripts337     until the rebuild scripts have run to completion; doing so could yield338     incorrect results or poor performance. Tables not referenced in rebuild339     scripts can be accessed immediately.340    </p></div></li><li class="step"><p class="title"><strong>Statistics</strong></p><p>341     Because optimizer statistics are not transferred by <code class="command">pg_upgrade</code>, you will342     be instructed to run a command to regenerate that information at the end343     of the upgrade.  You might need to set connection parameters to344     match your new cluster.345    </p></li><li class="step"><p class="title"><strong>Delete old cluster</strong></p><p>346     Once you are satisfied with the upgrade, you can delete the old347     cluster's data directories by running the script mentioned when348     <code class="command">pg_upgrade</code> completes. (Automatic deletion is not349     possible if you have user-defined tablespaces inside the old data350     directory.)  You can also delete the old installation directories351     (e.g., <code class="filename">bin</code>, <code class="filename">share</code>).352    </p></li><li class="step" id="PGUPGRADE-STEP-REVERT"><p class="title"><strong>Reverting to old cluster</strong></p><p>353     If, after running <code class="command">pg_upgrade</code>, you wish to revert to the old cluster,354     there are several options:355 356     </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>357        If the <code class="option">--check</code> option was used, the old cluster358        was unmodified;  it can be restarted.359       </p></li><li class="listitem"><p>360        If the <code class="option">--link</code> option was <span class="emphasis"><em>not</em></span>361        used, the old cluster was unmodified;  it can be restarted.362       </p></li><li class="listitem"><p>363        If the <code class="option">--link</code> option was used, the data364        files might be shared between the old and new cluster:365 366        </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "><li class="listitem"><p>367           If <code class="command">pg_upgrade</code> aborted before linking started,368           the old cluster was unmodified;  it can be restarted.369          </p></li><li class="listitem"><p>370           If you did <span class="emphasis"><em>not</em></span> start the new cluster, the old371           cluster was unmodified except that, when linking started, a372           <code class="literal">.old</code> suffix was appended to373           <code class="filename">$PGDATA/global/pg_control</code>.  To reuse the old374           cluster, remove the <code class="filename">.old</code> suffix from375           <code class="filename">$PGDATA/global/pg_control</code>; you can then restart376           the old cluster.377          </p></li><li class="listitem"><p>378           If you did start the new cluster, it has written to shared files379           and it is unsafe to use the old cluster.  The old cluster will380           need to be restored from backup in this case.381          </p></li></ul></div></li></ul></div></li></ol></div></div><div class="refsect1" id="id-1.9.5.12.8"><h2>Notes</h2><p>382   <span class="application">pg_upgrade</span> creates various working files, such383   as schema dumps, stored within <code class="filename">pg_upgrade_output.d</code> in384   the directory of the new cluster. Each run creates a new subdirectory named385   with a timestamp formatted as per ISO 8601386   (<code class="literal">%Y%m%dT%H%M%S</code>), where all its generated files are387   stored.388   <code class="filename">pg_upgrade_output.d</code> and its contained files will be389   removed automatically if <span class="application">pg_upgrade</span> completes390   successfully; but in the event of trouble, the files there may provide391   useful debugging information.392  </p><p>393   <span class="application">pg_upgrade</span> launches short-lived postmasters in394   the old and new data directories.  Temporary Unix socket files for395   communication with these postmasters are, by default, made in the current396   working directory.  In some situations the path name for the current397   directory might be too long to be a valid socket name.  In that case you398   can use the <code class="option">-s</code> option to put the socket files in some399   directory with a shorter path name.  For security, be sure that that400   directory is not readable or writable by any other users.401   (This is not supported on Windows.)402  </p><p>403   All failure, rebuild, and reindex cases will be reported by404   <span class="application">pg_upgrade</span> if they affect your installation;405   post-upgrade scripts to rebuild tables and indexes will be406   generated automatically.  If you are trying to automate the upgrade407   of many clusters, you should find that clusters with identical database408   schemas require the same post-upgrade steps for all cluster upgrades;409   this is because the post-upgrade steps are based on the database410   schemas, and not user data.411  </p><p>412   For deployment testing, create a schema-only copy of the old cluster,413   insert dummy data, and upgrade that.414  </p><p>415   <span class="application">pg_upgrade</span> does not support upgrading of databases416   containing table columns using these <code class="type">reg*</code> OID-referencing system data types:417   </p><table border="0" summary="Simple list" class="simplelist"><tr><td><code class="type">regcollation</code></td></tr><tr><td><code class="type">regconfig</code></td></tr><tr><td><code class="type">regdictionary</code></td></tr><tr><td><code class="type">regnamespace</code></td></tr><tr><td><code class="type">regoper</code></td></tr><tr><td><code class="type">regoperator</code></td></tr><tr><td><code class="type">regproc</code></td></tr><tr><td><code class="type">regprocedure</code></td></tr></table><p>418   (<code class="type">regclass</code>, <code class="type">regrole</code>, and <code class="type">regtype</code> can be upgraded.)419  </p><p>420   If you want to use link mode and you do not want your old cluster421   to be modified when the new cluster is started, consider using the clone mode.422   If that is not available, make a copy of the423   old cluster and upgrade that in link mode. To make a valid copy424   of the old cluster, use <code class="command">rsync</code> to create a dirty425   copy of the old cluster while the server is running, then shut down426   the old server and run <code class="command">rsync --checksum</code> again to update the427   copy with any changes to make it consistent.  (<code class="option">--checksum</code>428   is necessary because <code class="command">rsync</code> only has file modification-time429   granularity of one second.)  You might want to exclude some430   files, e.g., <code class="filename">postmaster.pid</code>, as documented in <a class="xref" href="continuous-archiving.html#BACKUP-LOWLEVEL-BASE-BACKUP" title="26.3.3. Making a Base Backup Using the Low Level API">Section 26.3.3</a>.  If your file system supports431   file system snapshots or copy-on-write file copies, you can use that432   to make a backup of the old cluster and tablespaces, though the snapshot433   and copies must be created simultaneously or while the database server434   is down.435  </p></div><div class="refsect1" id="id-1.9.5.12.9"><h2>See Also</h2><span class="simplelist"><a class="xref" href="app-initdb.html" title="initdb"><span class="refentrytitle"><span class="application">initdb</span></span></a>, <a class="xref" href="app-pg-ctl.html" title="pg_ctl"><span class="refentrytitle"><span class="application">pg_ctl</span></span></a>, <a class="xref" href="app-pgdump.html" title="pg_dump"><span class="refentrytitle"><span class="application">pg_dump</span></span></a>, <a class="xref" href="app-postgres.html" title="postgres"><span class="refentrytitle"><span class="application">postgres</span></span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="pgtesttiming.html" title="pg_test_timing">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="reference-server.html" title="PostgreSQL Server Applications">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="pgwaldump.html" title="pg_waldump">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="application">pg_test_timing</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> <span class="application">pg_waldump</span></td></tr></table></div></body></html>
codekingpro/portable-devtools · Team Ai