Add note about column privilege behavior to REVOKE reference page

suggested by Josh Berkus

diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index a390375c1747068f0cac9e41c061181d4b976675..202a2a35ab4744acc0ecb71816f3078b74b905c8 100644 (file)
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -162,6 +162,8 @@ REVOKE [ ADMIN OPTION FOR ]
   <para>
    When revoking privileges on a table, the corresponding column privileges
    (if any) are automatically revoked on each column of the table, as well.
+   On the other hand, if a role has been granted privileges on a table, then
+   revoking the same privileges from individual columns will have no effect.
   </para>
 
   <para>