doc: document "IS NOT DOCUMENT"

Reported-by: [email protected]
Discussion: https://postgr.es/m/152056505045.4963.16783351661813640274@wrigleys.postgresql.org

Author: Euler Taveira

Backpatch-through: 10

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index a11f3abc822653dce0921144b0ee7f7edd1e0bbf..5abb1c46fbb86eff5f2b3c4f8f27df4147d02e83 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -10399,6 +10399,24 @@ SELECT xmlagg(x) FROM (SELECT * FROM test ORDER BY y DESC) AS tab;
     
    
 
+   
+    <literal>IS NOT DOCUMENT</literal>
+
+    
+     IS NOT DOCUMENT
+    
+
+
+xml IS NOT DOCUMENT
+
+
+    
+     The expression IS NOT DOCUMENT returns false if the
+     argument XML value is a proper XML document, true if it is not (that is,
+     it is a content fragment), or null if the argument is null.
+    
+   
+
    
     <literal>XMLEXISTS</literal>