name BETWEEN 'A' AND 'D'

is the same as

name >= 'A' AND name <= 'D'

If the optimizer does a good job (Firebird 1.0.2 works OK, haven't
checked other versions), there should be no difference in performance
between the two. That you do not see any difference when using < 'D',
simply means that persons named D is as rare in your country as in
mine.

Set

--- In firebird-support@yahoogroups.com, James wrote:
> Hi
> I have been following this thread. What is the difference between
> NAME between 'A' and 'D' from NAME >= 'A' and NAME < 'D' I have try
> this in my database it seems to give me a similar result. Which one
> could use index to execute faster?