diff --git a/functions/pgsql.xml b/functions/pgsql.xml
index f172993bae..ace209db76 100644
--- a/functions/pgsql.xml
+++ b/functions/pgsql.xml
@@ -1027,6 +1027,50 @@ echo $row[1] . " <- row\n";
    </refsect1>
   </refentry>
 
+  <refentry id="function.pg-trace">
+   <refnamediv>
+    <refname>pg_trace</refname>
+    <refpurpose>Trace a connection to PostgreSQL server</refpurpose>
+   </refnamediv>
+   <refsect1>
+    <title>Description</title>
+    <funcsynopsis>
+     <funcdef>bool <function>pg_trace</function></funcdef>
+     <paramdef>string
+      <parameter>filename</parameter>
+     </paramdef>
+     <paramdef>string
+      <parameter><optional>mode</optional></parameter>
+     </paramdef>
+     <paramdef>int
+      <parameter><optional>connection</optional></parameter>
+     </paramdef>
+    </funcsynopsis>
+    <para>
+     Enables tracing of the PostgreSQL frontend/backend communication
+     to a debugging file. To fully understand the results one needs to be
+     familiar with the internals of PostgreSQL communication protocol.
+     For those who are not, it can still be useful for tracing errors in
+     queries sent to the server, you could do for example
+     'grep '^To backend' trace.log' and see what queriew actually were sent
+     to the PostgreSQL server.
+    </para>
+    <para>
+     <argument>filename</argument> and <argument>mode</argument> are the
+     same as in <function>fopen</function> (<argument>mode</argument> defaults
+     to 'w'), <argument>connection</argument> specifies the connection to
+     trace and defaults to the last one opened.
+    </para>
+    <para>
+     Returns TRUE if <argument>filename</argument> could be opened for
+     logging, FALSE otherwise.
+    </para>
+    <para>
+     See also <function>fopen</function> and <function>pg_untrace</function>.
+    </para>
+   </refsect1>
+  </refentry>
+
   <refentry id="function.pg-tty">
    <refnamediv>
     <refname>pg_tty</refname>
@@ -1046,6 +1090,33 @@ echo $row[1] . " <- row\n";
    </refsect1>
   </refentry>
 
+  <refentry id="function.pg-untrace">
+   <refnamediv>
+    <refname>pg_untrace</refname>
+    <refpurpose>Stop tracing a connection to PostgreSQL server</refpurpose>
+   </refnamediv>
+   <refsect1>
+    <title>Description</title>
+    <funcsynopsis>
+     <funcdef>bool <function>pg_untrace</function></funcdef>
+     <paramdef>int
+      <parameter><optional>connection</optional></parameter>
+     </paramdef>
+    </funcsynopsis>
+    <para>
+     Stop tracing started by <function>pg_trace</function>.
+     <argument>connection</argument> specifies the connection that was
+     traced and defaults to the last one opened.
+    </para>
+    <para>
+     Returns always TRUE.
+    </para>
+    <para>
+     See also <function>pg_trace</function>.
+    </para>
+   </refsect1>
+  </refentry>
+
  </reference>
 
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