"Telemachus" <telemachus_at_ulysseswillreturn.net> wrote in message news:<_TLta.12006$pK2.15734_at_news.indigo.ie>...
> Snippety Snip
>
> It only works when there's NOT NULL constraints... not a condition...
>
> i.e. where <X> is not null in the query will not get the HJ to work. it
> must be a constraint.
>
> It's one of the <few> constraint-based optimizations. It used to be
> documented in 7.3 manuals but it's now left out for some reason.
>
> Otherwise you tend to get a nasty FILTER operation
its actually the to_char that was getting in the way. Took that out
and it worked. Very small performance improvement unfortunately. Only
5%. Blah... hate when that happens.
Received on Tue May 06 2003 - 09:35:52 CDT
