doc: improve description of subscripting of arrays

bmomjian · bmomjian · commit 06eba0fd10b1 · 2020-08-31T13:49:17.000-04:00
It wasn't clear the non-integers are cast to integers for subscripting, rather than throwing an error. Reported-by: sean@materialize.io Discussion: https://postgr.es/m/159538675800.624.7728794628229799531@wrigleys.postgresql.org Backpatch-through: 9.5
diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml
@@ -1359,7 +1359,7 @@ CREATE FUNCTION dept(text) RETURNS dept
 </synopsis>
     (Here, the brackets <literal>[ ]</literal> are meant to appear literally.)
     Each <replaceable>subscript</replaceable> is itself an expression,
-    which must yield an integer value.
+    which will be rounded to the nearest integer value.
    </para>
 
    <para>
