Perhaps because doing it in SQL, you can take advantage of the indexes and groupings the database provides, rather than having to fetch the whole set and then discard data in your script ? For instance, there's 1000 matches for any day within the range, however you want to display them 25 items at a time - do you fetch 1000 items each time, throwing away an unknown amount of records to find the first 25, then do the same on the second page request for the next 25 ? Or would it be more elegant to just ask the database 'records 26-50 matching these criteria, please ?' ?