DOC: updated pg-wrapper documentation

Author: Liudmila Mantrova

doc/src/sgml/ref/pg-wrapper.sgml

@@ -115,26 +115,46 @@
     to the provided client and server programs, as well as add
     <acronym>SQL</acronym> man pages to the man page configuration file.
     </para>
-    <para>
-      If <acronym>SQL</acronym> man pages are already installed
-      from a different product, the previous installation will keep
-      its priority. For the new <acronym>SQL</acronym> documentation
-      to be displayed first, you have to modify the system configuration,
-      for example, change the <envar>MANPATH</envar> value.
-    </para>
-    <important>
-     <para>
-       If you have been using the same programs provided with
-       other products, running <application>pg-wrapper</application> may result in a conflict.
-       In this case, you can either continue using the already
-       available program version, or adjust the settings manually.
-     </para>
      <para>
-       Alternatively, you can add <filename>/opt/pgpro/std-&majorversion;/bin</filename>
-       before <filename>/usr/bin</filename> into your <envar>PATH</envar> to
-       make these programs available just for a particular user or user session.
+        For parallel installations with other <filename>PostgreSQL</filename>-based
+        products, <filename>pg-wrapper</filename> behavior depends
+        on whether the <application>update-alternatives</application> utility
+        is supported by your system and the already installed
+        <filename>PostgreSQL</filename>-based product:
+      <itemizedlist>
+        <listitem>
+          <para>
+            If <application>update-alternatives</application> is supported,
+            <filename>pg-wrapper</filename> adds symbolic links to <productname>&productname;</productname>
+            programs into the alternative system, in accordance with their priority, as well as adds
+            <acronym>SQL</acronym> man pages to the man page configuration file.
+            For details on how to change the alternatives system priorities,
+            see the man page for <application>update-alternatives</application>
+            on your system.
+          </para>
+          <para>
+            If <acronym>SQL</acronym> man pages are already installed from a different product,
+            the pages unique for the new installation will be displayed,
+            while the previous installation will keep its priority for all the coinciding
+            man pages. For the new <acronym>SQL</acronym> documentation to be displayed
+            for all pages, you have to modify the system configuration,
+            for example, change the <envar>MANPATH</envar> value.
+          </para>
+        </listitem>
+        <listitem>
+          <para>
+            If <application>update-alternatives</application> is not supported,
+            <filename>pg-wrapper</filename> updates the system configuration
+            only if there are no conflicts with any programs or man pages already installed.
+            Otherwise, <application>pg-wrapper</application> does not create or update
+            any program links and skips <acronym>SQL</acronym> man page integration. In this case,
+            you can either continue using the already available program versions and <acronym>SQL</acronym> man pages,
+            or modify the <envar>PATH</envar> and <envar>MANPATH</envar>
+            settings manually.
+          </para>
+        </listitem>
+      </itemizedlist>
      </para>
-    </important>
 
   <para>
     For details on binary installation specifics on Linux,