=centercr
@ []Query Q 4.2.1: When was the Toy department's budget constant and greater than
$175K for more than one year?
Answer: ``$200K from 01-Jan-1984 to 31-Dec-1986.''
Category: (Projected, Interval, Derived) / (Duration, Interval, Supplied) /
(≠, Constant) (=, Constant)
=centercr
@ []Query Q 4.2.2: When was the Toy department's budget constant and greater than
$175K for more than one year, and who was the manager for that time?
Answer: ``$200K from 01-Jan-1984 to 31-Dec-1986, managed by Di.''
Category: (Complete, Interval, Derived) / (Duration, Interval, Supplied) /
(≠, Constant) (=, Constant)
=centercr
@ []Query Q 4.2.3: When did the Toy department's budget exceed $175K and then
continue unchanged for a year?
Answer: ``$200K at 01-Jan-1984.''
Category: (Projected, Event, Derived) / (Duration, Interval, Supplied) / (≠,
Constant) (=, Constant)
=centercr
@ []Query Q 4.2.4: Who managed departments (and when) whose budgets exceeded
$175K and then held constant for at year?
Answer: ``Di, from 01-Aug-1984 to 31-Dec-1986.''
Category: (Projected, Interval, Derived) / (Duration, Interval, Supplied) /
(=, Constant) (=, Foreign)
=centercr
@ []Query Q 4.2.5: What departments were in continuous operation (and when) longer
than the duration between Ed's and Di's birthdates?
Answer: ``Toy, from 01-Jan-1982 to present.''
Category: (Projected, Interval, Derived) / (Duration, Interval,
User-defined) / (=, Constant) (=, Constant)
Values computed from attribute values of type user-defined time don't quite fit the taxonomy. Also, the books department is not included in the answer to the last query, because it started operation on 01-Apr-87, which is less than five years before now (01-Jan-1990).