>Naomi,
>
>1) I doubt the table is so large that it'd make much difference, and if the table so large it should be in a higher performance database engine for lots of reasons.
>
>2) This also seems like it's a once-a-day or once-a-week query to send out a company email wishing people happy birthday
>
>3) I can't imagine too many person tables that'd bother building an index on DOB that's not a field used for filtering many results so the cost of a table scan isn't all that bad (see item 1).
>
>>I don't really like all the suggestions, because they don't use existing index on date, if there is an index. I think we need to convert ldStart and ldEnd to the year of DOB and not vs. versa.

We have an index on DOB because we perform searches on this field (within a range).