> Also, what are the case insensitive collations in firebird that are
> english? Is unicode_ci_ai the only one?

There also is UNICODE_CI, which is case insensitive but not accent
insensitive.

> Would using an case insensitive collation like unicode_ci_ai affect
> performance?

Sure. Applying a collation means that characters have to be
looked up in tables. The question is *how much* this affects
performance. You'll probably have to do your own tests.

Regards

Stefan