Patrick Welche writes:
> I think this is right..
No, it's talking about relational algebra, not SQL.
>
> Patrick
>
> Index: sql.sgml
> ===================================================================
> RCS file: /projects/cvsroot/pgsql/doc/src/sgml/sql.sgml,v
> retrieving revision 1.24
> diff -p -r1.24 sql.sgml
> *** sql.sgml 2001/10/23 16:42:36 1.24
> --- sql.sgml 2002/02/11 15:37:47
> *************** attributes are taken from. We often writ
> *** 488,494 ****
>
> <listitem>
> <para>
> ! DIFFERENCE (− or ∖): builds the set difference of
> two tables. Let <classname>R</classname> and <classname>S</classname>
> again be two tables with the same
> arity. <classname>R</classname> - <classname>S</classname>
> --- 488,494 ----
>
> <listitem>
> <para>
> ! EXCEPT (− or ∖): builds the set difference of
> two tables. Let <classname>R</classname> and <classname>S</classname>
> again be two tables with the same
> arity. <classname>R</classname> - <classname>S</classname>
>
--
Peter Eisentraut peter_e@gmx.net