Revisiting the Definition of the Relational Tuple CalculusThe tuple relational calculus has been based on the classical predicate logics. Databases are however not exactly representable in this calculus. They are finite. This finiteness results in a......
The variant of relational calculus that is used in this tutorial is thetuple relational calculus. The first formal definition fortuple relational calculusis due to Codd (1972), who also developed an algorithm to translate from relational calculus to relational algebra, another theoretical query languag...
This paper defines aggregates in the temporal query language TQuel provides their formal semantics in the tuple relational calculus. A formal semantics for Quel aggregates is defined in the process. Multiple aggregates; aggregates appearing in the where, when, valid, and as-of clauses; nested ...
Related to Relational calculus:Tuple relational calculus re·la·tion·al (rĭ-lā′shə-nəl) adj. 1.Of or arising from kinship. 2.Indicating or constituting relation. 3.GrammarOf, relating to, or being a word or particle, such as a conjunction or preposition, that expresses a synta...
摘要: This paper defines new constructs to support aggregation in the temporal query language TQuel and presents their formal semantics in the tuple relational calculus. A formal semantics for Quel aggre...关键词: TQuel formal semantics historical algebra nested aggregation query languages relational ...
tuple calculus (database) A form ofrelational calculusin which a variable's only permitted values are tuples of a givenrelation. Codd's unimplemented languageALPHAand the subsequentQUELare examples of the tuple calculus. This article is provided by FOLDOC - Free Online Dictionary of Computing (fo...
Tuple Relational Calculus: Constraints: ΦΦ :...The expressive power of the bounded-iteration construct - Qian - 1991X. Qian. The expressive power of the bounded-iteration con- struct. Acta Informatica, 28(7):631-656, 1991.The expressive power of the bounded-iteration construct - Qian - ...
By f, t we denote empty set 0 and singleton set {<>}, respectively (with the empty tuple <> i.e., the unique tuple of 0-ary relation), which may be thought of as falsity f and truth t, as those used in the relational algebra. For a given domain D, we define that [D.sup....
Domain Relational Calculus: { <person_name, street, city> | ∃e(employee(person_name, street, city) ∧ ¬∃w(works(person_name, "First Bank Corporation", _))) } g. Tuple Relational Calculus: { e1 | employee(e1) ∧ ∀e2(employee(e2) ∧ works(w2, e2.person_name, "SmallS...
. If we let X(z) be the tuple of numbers defined by the number of edges, the number of vertices, the volume of z and the surface area and let Y(z) be the number of faces, then without knowing z, the question becomes is there a function f: R4 -> R such that f( X(z) ) ...