PLANanalyser (see the link in www.ibphoenix.com in 'misc' section)
has some good documentation. I also found this:

http://bdn.borland.com/article/0,1410,26293,00.html

Which is really interesting. I now know I shouldn't try to write my
own PLAN expressions! Only sculpt the SQL to lead the planner into
being as efficient as possible.

This any good to you??

John

--- In firebird-support@yahoogroups.com, Uwe Oeder <uweo@c...> wrote:
> When you get anything please let me know I am also very interested.
>
> At 01:58 PM 3/14/2004, you wrote:
> >Can anyone point me to a reference doc for understanding / writing
> >PLAN expressions?
> >
> >Since the built-in planner isn't always 100%, it's something I
> >figure I should learn more about.
> >
> >Thanks,
> >
> >John
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> >
> >
> >