Document use of partial indexes for partial unique constraints

bmomjian · bmomjian · commit 4b224011751d · 2014-09-03T14:32:57.000-04:00
Report by Tomáš Greif

Backpatch through 9.4
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
@@ -546,7 +546,9 @@ CREATE TABLE products (
 
    <para>
     Adding a unique constraint will automatically create a unique btree
-    index on the column or group of columns used in the constraint.
+    index on the column or group of columns used in the constraint. 
+    A uniqueness constraint on only some rows can be enforced by creating
+    a <link linkend="indexes-partial">partial index</link>.
    </para>
 
    <indexterm>
