Support "variadic" functions, which can accept a variable number of arguments

so long as all the trailing arguments are of the same (non-array) type.
The function receives them as a single array argument (which is why they
have to all be the same type).

It might be useful to extend this facility to aggregates, but this patch
doesn't do that.

This patch imposes a noticeable slowdown on function lookup --- a follow-on
patch will fix that by adding a redundant column to pg_proc.

Pavel Stehule

1 files changed, 6 insertions, 5 deletions

diff --git a/doc/src/sgml/ref/alter_function.sgml b/doc/src/sgml/ref/alter_function.sgml
index bee2f6f4390..abedfe7d50b 100644
--- a/doc/src/sgml/ref/alter_function.sgml
+++ b/doc/src/sgml/ref/alter_function.sgml
@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/alter_function.sgml,v 1.15 2007/09/03 18:46:29 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/alter_function.sgml,v 1.16 2008/07/16 01:30:21 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -81,13 +81,14 @@ where <replaceable class="PARAMETER">action</replaceable> is one of:
 
     <listitem>
      <para>
-      The mode of an argument: either <literal>IN</>, <literal>OUT</>,
-      or <literal>INOUT</>.  If omitted, the default is <literal>IN</>.
+      The mode of an argument: <literal>IN</>, <literal>OUT</>,
+      <literal>INOUT</>, or <literal>VARIADIC</>.
+      If omitted, the default is <literal>IN</>.
       Note that <command>ALTER FUNCTION</command> does not actually pay
       any attention to <literal>OUT</> arguments, since only the input
       arguments are needed to determine the function's identity.
-      So it is sufficient to list the <literal>IN</> and <literal>INOUT</>
-      arguments.
+      So it is sufficient to list the <literal>IN</>, <literal>INOUT</>,
+      and <literal>VARIADIC</> arguments.
      </para>
     </listitem>
    </varlistentry>