On Fri, Jul 13, 2012 at 9:51 AM, Craig Ringer
<craig@postnewspapers.com.au> wrote:
> ... but it feels like there must be a smarter way.
Well, may be kind of (h1 - h2), (h2 - h1) and derivatives will make sense?
--
Sergey Konoplev
a database architect, software developer at PostgreSQL-Consulting.com
http://www.postgresql-consulting.com
Jabber: gray.ru@gmail.com Skype: gray-hemp Phone: +79160686204