BETWEEN transformations A BETWEEN predicate is transformed into equivalent predicates that use the >= and <= operators, which are optimizable. BETWEEN transformations Internal transformation of statementsBETWEEN predicates

For example,

flight_date BETWEEN DATE('2005-04-01') and DATE('2005-04-10')

is transformed into

flight_date >= DATE('2005-04-01') AND flight_date >= '2005-04-10'