archive: Document pgdg vs pgdg-archive

diff --git a/archive/index.html b/archive/index.html
index 36cbd3397b12a8b52c53b10e9d7a695dbb0c0d4b..aed7d1f81e5533516b207a43360d3ec7c45ab2b0 100644 (file)
--- a/archive/index.html
+++ b/archive/index.html
@@ -8,16 +8,44 @@ since April 2013. The oldest PostgreSQL server versions covered are 8.2.23,
 </p>
 
 <p>
-/etc/apt/sources.list entry for the archive repository:
+Available distributions are listed in
+<a href="/pub/repos/apt/dists/index.html">/pub/repos/apt/dists/</a>.
+</p>
+
+<p>
+To browse directories, be sure to append "/index.html" to the URL.
+</p>
+
+<h2>Archive of distributions removed from apt.postgresql.org</h2>
+
+<p>
+Distribution releases are moved here from apt.postgresql.org after they have
+been EOLed by Debian or Ubuntu. The distributions retain their original
+<b>DIST-pgdg</b> name. Like on apt.postgresql.org, only the most recent version
+of each package is contained.
+<p>
+
+<p>
+/etc/apt/sources.list entry for the distribution archive:
 <b><pre>
-deb https://apt-archive.postgresql.org/pub/repos/apt DIST-pgdg-archive main
-deb-src https://apt-archive.postgresql.org/pub/repos/apt DIST-pgdg-archive main
+deb https://apt-archive.postgresql.org/pub/repos/apt DIST-pgdg main
+deb-src https://apt-archive.postgresql.org/pub/repos/apt DIST-pgdg main
 </pre></b>
 Replace <em>DIST</em> by the Debian/Ubuntu distribution in question, e.g.
-buster, stretch, focal, bionic, ... Available distributions are listed in
-<a href="/pub/repos/apt/dists/index.html">/pub/repos/apt/dists/</a>.
+buster, stretch, focal, bionic, ...
 </p>
 
+<h2>Archive of all released packages on apt.postgresql.org</h2>
+
+The archive also contains all versions of all packages that have been part of
+some <em>DIST-pgdg</em> distribution on apt.postgresql.org. These distributions
+are called <b>DIST-pgdg-archive</b> here. The archive is updated daily; the
+Packages/Sources files contain all versions at once.
+
 <p>
-To browse directories, be sure to append "/index.html" to the URL.
+/etc/apt/sources.list entry for the archive repository:
+<b><pre>
+deb https://apt-archive.postgresql.org/pub/repos/apt DIST-pgdg-archive main
+deb-src https://apt-archive.postgresql.org/pub/repos/apt DIST-pgdg-archive main
+</pre></b>
 </p>