Improve documentation note about Python 2.3 and cdecimal.

Explain exactly what fails (ie, function arguments of type numeric)
if you don't have it.

diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index 1dee8f4ccba1470a0a1c2e77c0ae64a9bbe76a4b..efaaad80b402fa0657a0b4e4ce3796919c68bb8a 100644 (file)
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -204,10 +204,10 @@ su - postgres
       installation with the header files and
       the distutils module.  The minimum
       required version is Python 2.3.
-      For full functionality, a 2.3.x installation must include the
-      separately-available cdecimal module; in particular
-      the PL/Python regression tests will not pass if that
-      is missing.
+      (To work with function arguments of type numeric, a 2.3.x
+      installation must include the separately-available cdecimal
+      module; note the PL/Python regression tests
+      will not pass if that is missing.)
       Python 3 is supported if it's
       version 3.1 or later; but see
       PL/Python documentation]]>