Linear vs Polynomial Constraints in Database Query Languages
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چکیده
We prove positive and negative results on the expressive power of the relational calculus augmented with linear constraints. We show non-expressibility of some properties expressed by polynomial constraints. We also show expressibility of some queries involving existence of lines, when the query output has a simple geometrical relation to the input. Finally, we compare the expressive power of linear vs. polynomial constraints in the presence of a discrete order.
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تاریخ انتشار 1994