doc: Add note about how to use pg_overexplain.

nathan-bossart · nathan-bossart · commit c4b5cd095675 · 2025-07-17T10:25:59.000-05:00
This commit adds a note to the pg_overexplain page that describes how to use it (LOAD, session_preload_libraries, or shared_preload_libraries). The new text is mostly lifted from the auto_explain page. We should probably consider centralizing this information in the future. While at it, add a missing "module" to the opening sentence. Reviewed-by: "David G. Johnston" <david.g.johnston@gmail.com> Reviewed-by: Robert Treat <rob@xzilla.net> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Discussion: https://postgr.es/m/aHVWKM8l8kLlZzgv%40nathan Backpatch-through: 18
diff --git a/doc/src/sgml/pgoverexplain.sgml b/doc/src/sgml/pgoverexplain.sgml
@@ -8,7 +8,7 @@
  </indexterm>
 
  <para>
-  The <filename>pg_overexplain</filename> extends <command>EXPLAIN</command>
+  The <filename>pg_overexplain</filename> module extends <command>EXPLAIN</command>
   with new options that provide additional output. It is mostly intended to
   assist with debugging of and development of the planner, rather than for
   general use. Since this module displays internal details of planner data
@@ -17,6 +17,21 @@
   often as) those data structures change.
  </para>
 
+ <para>
+  To use it, simply load it into the server.  You can load it into an
+  individual session:
+
+<programlisting>
+LOAD 'pg_overexplain';
+</programlisting>
+
+  You can also preload it into some or all sessions by including
+  <literal>pg_overexplain</literal> in
+  <xref linkend="guc-session-preload-libraries"/> or
+  <xref linkend="guc-shared-preload-libraries"/> in
+  <filename>postgresql.conf</filename>.
+ </para>
+
  <sect2 id="pgoverexplain-debug">
   <title>EXPLAIN (DEBUG)</title>
 
