> > > to quote Celko
> > > "An EXISTS predicate can use indexes to find.. or fail, whereas the IN
> > > predicate ofen has to build the results of the subquery in a working
> >table"
> > >
> > > not sure exactly how FB is optimised in this regard
> >
> >Celko is talking rubbish here. "can use indexes" -> this is

implementation

> >defined. How an engine handles whatever statement has nothing to do
> >with the logical operator "EXISTS" or "IN".
>
> True, Celko uses Oracle for his examples. He does have a certain

blindness

> with regard to standard SQL and implementation-specific stuff.


>He's still
> worth paying attention to, esp. in the "Puzzles" stuff.

I guess we all have our "good" moments :-)

--
Martijn