=centercr
@ []Query Q 2.4.1: Who managed the Book department for at least two years?
Answer: ``None''
Category: (Projected, None) / (Duration, Element, Explicit) / (=, Constant)
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@ []Query Q 2.4.2: Which employees had the same salary for at least three years?
Answer: ``Di''
Category: (Projected, None) / (Duration, Element, Explicit) /
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@ []Query Q 2.4.3: Who worked for the same manager for at least five years?
Answer: ``Ed'' and ``Di''
Category: (Projected, None) / (Duration, Element, Explicit) /
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@ []Query Q 2.4.4: Who worked in a department for less than 6 months total?
Answer: ``None''
Category: (Projected, None) / (Duration, Element, Explicit) /
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@ []Query Q 2.4.5: Who had a position in the Toy department and a salary of 50K for at
least two years?
Answer: ``Di''
Category: (Projected, None) / (Duration, Element, Explicit) / (=, Constant) (=, Constant)
This query and the next illustrate the dependence on complete
understanding in formulating a query. The syntax is almost the same, but the
interpretation of ``and'' is different. In the above, ``and'' becomes temporal
intersection while in the next query, it is merely logical conjunction.
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@ []Query Q 2.4.6: Who had a position in the Toy department and a position in the Book
department for at least two years?
Answer: ``None''
Category: (Projected, None) / (Duration, Element, Explicit) / (=, Constant) (=, Constant)
=centercr
@ []Query Q 2.4.7: Who worked for the same manager for total time of at least
five years?
Answer: ``Ed'' and ``Di''
Category: (Projected, None) / (Duration, Element, Explicit) /