> >> So I wonder if this is the right approach. I tried to put indexes on
> >> some fields like AUTHOR and TITLE, but I think the use of UPPER in the
> >> ON-clause prevents using these indexes.
>
> > That is correct, UPPER removes the ability to use an index. In
> > Firebird 2, you could use expression based indices, in Firebird
> > 1.5 or lower, I suggest you add a shadow field, eg: TITLE_UPPER,
> > which you populate by using a before insert/update trigger and
> > use that to do your compare... Considering the number of books
> > with the same title, this should be quick quicker.
>
> How about an index on a computed field ?

I guess you haven't tried? :-)

Those cannot be created.

Martijn Tonies
Database Workbench - development tool for Firebird and more!
Upscene Productions
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