> > Since the performance difference is quite big, does this mean that I
> > have to rewrite all my LEFT JOIN queries?
> No, you see the difference only in execution time.
> To compare the REAL speed between the two you must also
> include fetch-all and then you'll see they are almost the same.

OK. I suspected as much...:)
So you'd suggest leaving the LEFT JOINs as it is?
My problem here is that the user will invariably see the 'subquery'
version as way faster; the 60 seconds delay before the first page
appears is going to be a problem.

> If you don't have it, download the great tool below :
> http://delphi.weblogs.com/IBPLANalyzer

Thank you for the pointer. I think I saw this tool before, but since
it's only for Interbase, I didn't download it.

> One question from my site :
> What are your database-settings ?
> - Page Buffers ?

2048 (default on IB1.5beta3).
I was reluctant to change this setting since (again) I think I read a
posting here that says that there's a possibility that a bigger cache is
actually slowing things down.

> - PageSize ?

8192.
I saw some tools (IBAccess?) allowing 16K and 32K page sizes, but never
got these to work.

Many thanks.
sugi.