On Thu, Jan 12, 2006 at 07:51:22PM +0100, Ott? Havasv?lgyi wrote:
> Hi,
>
> If the join is to a primary key or notnull unique column(s), then
> inner join is also ok. But of course left join is the simpler case.
> An example:
Actually, you need both the unique/pk constraint, and RI (a fact I
missed in the email I just sent). Nullability is another consideration
as well. But there certainly are some pretty common cases that can be
optimized for.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461