Add warning about DOMAINs.

David Fetter

diff --git a/doc/src/sgml/ref/create_domain.sgml b/doc/src/sgml/ref/create_domain.sgml
index 1c3eb357c0442c58ef5f8fdbefbdab26fcabe06f..bddfb572875c806c6f9108f7bfe714910d600af5 100644 (file)
--- a/doc/src/sgml/ref/create_domain.sgml
+++ b/doc/src/sgml/ref/create_domain.sgml
@@ -1,5 +1,5 @@
 
 
@@ -48,10 +48,13 @@ where constraint is:
   
 
   
-   Domains are useful for abstracting common fields between tables into
-   a single location for maintenance.  For example, an email address column may be used
-   in several tables, all with the same properties.  Define a domain and
-   use that rather than setting up each table's constraints individually.
+   Domains are useful for abstracting common fields between tables
+   into a single location for maintenance.  For example, an email address
+   column may be used in several tables, all with the same properties.
+   Define a domain and use that rather than setting up each table's
+   constraints individually. Keep in mind also that declaring a
+   function result value as a domain is pretty dangerous, because none of
+   the PLs enforce domain constraints on their results.