Custom fields schema

[Daniel Berlin]

>
> (1) We've found that for excessively complex queries, generating them
> in cron and dumping them as HTML is useful. That is just the
> unfortunate reality at times.
>
However, if you remember correctly, one of gnome's expensive reports, the 
weekly status summary, was slow because of deficiencies in mysql's 
query optimizer.
I changed the query ever so slightly to convince mysql to do it the right 
way, and it became roughly 10 times faster.

--Dan