--- In firebird-support@yahoogroups.com, Jakub Hegenbart
<Kyosuke@s...> wrote:

> I'm not sure I understand. You say that FB can't use the same index

both to join/filter and to sort...

>
> But in a book I have (the only one in Czech, written by Pavel Cisar)

- if i remenber it correctly - there's a statement that if FB reports
in the query plan that it's going to ORDER the rows using index, one
can't tell whether it's going also to FILTER using the index or not.
This sentence would imply that it IS possible and that it happens.
I'll take one more look into the book, but the opposite wouldn't make
any sense for me since it's trivial to use the ORDERED-employed index
also to filter rows.

Jakub, seems I was'nt precise enough and you forgot context of
discussion. I meant some segments to filter, another segments to sort.

> Yes, I'm aware of these limitations. Is it going to change in

sometime in the future?

Dunno. Hope yes, I often use explicit plans though most of
developers call them 'ugly hack' ;)

Best regards,
Alexander.