TRUNC or BETWEEN?

I'm wondering if either of these functions/methods in Oracle 7 will turn off any indexes and perform full-table scans.

I'm trying to receive rows from our database, where the effective date is between the start and end dates stored on the row. Currently, we're using TRUNC(), because we don't care about the time, just the date itself. So,

...and trunc(a.start_date) <= 'entered date'

           and trunc(a.end_date) > 'entered date'

We had also considered using

...and 'entered date' between a.start_date and a.end_date

but were told that between shut off indexes. Now, I'm being told that TRUNC() turns off indexes. Anyone ever hear of either of these? Thanks. Received on Thu Feb 02 1995 - 21:36:09 CET