binary, you must specify
         <literal>DTRACEFLAGS="-64"</literal>.  For example,
         using the GCC compiler:
<screen>
./configure CC='gcc -m64' --enable-dtrace DTRACEFLAGS='-64' ...
</screen>
         Using Sun's compiler:
<screen>
./configure CC='/opt/SUNWspro/bin/cc -xtarget=native64' --enable-dtrace DTRACEFLAGS='-64' ...
</screen>
        </para>
       </listitem>
      </varlistentry>

      <varlistentry id="configure-option-enable-injection-points">
       <term><option>--enable-injection-points</option></term>
       <listitem>
        <para>
         Compiles <productname>PostgreSQL</productname> with support for
         injection points in the server. Injection points allow to run
         user-defined code from within the server in pre-defined code paths.
         This helps in testing and in the investigation of concurrency scenarios
         in a controlled fashion. This option is disabled by default.  See
         <xref linkend="xfunc-addin-injection-points"/> for more details.  This
         option is intended to be used only by developers for testing.
        </para>
       </listitem>
      </varlistentry>

      <varlistentry id="configure-option-with-segsize-blocks">
       <term><option>--with-segsize-blocks=SEGSIZE_BLOCKS</option></term>
       <listitem>
        <para>
         Specify the relation segment size in blocks. If both
         <option>--with-segsize</option> and this option are specified, this
         option wins.

         This option is only for developers, to test segment related code.
        </para>
       </listitem>
      </varlistentry>

     </variablelist>

   </sect3>

  </sect2>

  <sect2 id="configure-envvars">
   <title><filename>configure</filename> Environment Variables</title>

   <indexterm zone="configure-envvars">
    <primary>configure environment variables</primary>
   </indexterm>

    <para>
     In addition to the ordinary command-line options described above,
     <filename>configure</filename> responds to a number of environment
     variables.
     You can specify environment variables on the
     <filename>configure</filename> command line, for example:
<screen>
<userinput>./configure CC=/opt/bin/gcc CFLAGS='-O2 -pipe'</userinput>
</screen>
     In this usage an environment variable is little different from a
     command-line option.
     You can also set such variables beforehand:
<screen>
<userinput>export CC=/opt/bin/gcc</userinput>
<userinput>export CFLAGS='-O2 -pipe'</userinput>
<userinput>./configure</userinput>
</screen>
     This usage can be convenient because many programs' configuration
     scripts respond to these variables in similar ways.
    </para>

    <para>
     The most commonly used of these environment variables are
     <envar>CC</envar> and <envar>CFLAGS</envar>.
     If you prefer a C compiler different from the one
     <filename>configure</filename> picks, you can set the
     variable <envar>CC</envar> to the program of your choice.
     By default, <filename>configure</filename> will pick
     <filename>gcc</filename> if available, else the platform's
     default (usually <filename>cc</filename>).  Similarly, you can override the
     default compiler flags if needed with the <envar>CFLAGS</envar> variable.
    </para>

    <para>
     Here is a list of the significant variables that can be set in
     this manner:

     <variablelist>
      <varlistentry id="configure-envvars-bison">
       <term><envar>BISON</envar></term>
       <listitem>
        <para>
         Bison program
        </para>
       </listitem>
      </varlistentry>

      <varlistentry id="configure-envvars-cc">
       <term><envar>CC</envar></term>
       <listitem>
        <para>
         C compiler
        </para>
       </listitem>
      </varlistentry>

      <varlistentry id="configure-envvars-cflags">
       <term><envar>CFLAGS</envar></term>
       <listitem>
        <para>
         options to pass to the C compiler
        </para>
       </listitem>