On 25-2-2012 20:11, Aldo Caruso wrote:

> Mark,
>
> I really don't know why, in the Debian stable version, the Firebird
> SS package isn't the final one but a Release Candidate.
> On the other hand, your advice worked fine, although I don't figure
> why.
> In this context, an EXIST clause is more efficient than a IN
> clause, but both should be equivalent.
> Nevertheless, your advice worked.

IN and EXISTS have an equivalent result (if used in the right way), but
in implementation they are not the same. My advice btw came straight
from CORE-3211 :)

Mark
--
Mark Rotteveel