Any optimizations to the join code in 7.1?

Hello.

I have a particular query which performs a 15-way join; I believe in 
normalization ;-). Under 7.0.3, using the defaults where GEQO is 
enabled after 11, the query (which returns 1 row) takes 10 seconds. 
With GEQO turned off, it takes 18 seconds. Naturally I intend to 
upgrade as soon as possible, but I looked through the change log and 
didn't see anything specific WRT large joins. I was wondering if any 
work had been done in that area for 7.1. I realize you can only 
squeeze so much blood from stone, but....

Thanks for any info,

Mike Mascari
mascarm@mascari.com