Add note that not all SQL commands support ONLY in the same way.

diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 6c89170b34930a92d91c5c51d46ddd20900fedde..f32c1fc70d8d3cfd9e3e0620e02d845a0a851c8f 100644 (file)
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  Data Definition
@@ -2136,6 +2136,23 @@ VALUES ('New York', NULL, NULL, 'NY');
    permissions on it.
   
 
+  
+   More generally, note that not all SQL commands are able to work on
+   inheritance hierarchies.  Commands that are used for data querying,
+   data modification, or schema modification
+   (e.g., SELECT, UPDATE, DELETE,
+   most variants of ALTER TABLE, but
+   not INSERT and ALTER TABLE ...
+   RENAME) typically default to including child tables and
+   support the ONLY notation to exclude them.
+   Commands that do database maintenance and tuning
+   (e.g., REINDEX, VACUUM)
+   typically only work on individual, physical tables and do no
+   support recursing over inheritance hierarchies.  The respective
+   behavior of each individual command is documented in the reference
+   part ().
+  
+
   
    A serious limitation of the inheritance feature is that indexes (including
    unique constraints) and foreign key constraints only apply to single