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A functional Dependency_theory_(database_theory)(FD) is a constraint between two sets of attributes in a Relational_modelfrom a Database
Given a relation R, a set of Attribute_(computing) X in R is said to functionally determineanother attribute Y, also in R, (written X → Y) if and only if each X value is associated with precisely one Y value. Customarily we call X the determinant set and Y the dependent attribute. Thus, given a Tupleand the values of the attributes in X, one can determine the corresponding value of the Y attribute. For the purposes of simplicity, given that X and Y are sets of attributes in R, X → Y denotes that X functionally determines each of the members of Y - in this case Yis known as the dependent set. Thus, a Candidate_keyis a minimal set of attributes that functionally determine all of the attributes in a relation.(Note: the "function" being discussed in "functional dependency" is the function of Identification_(information).)
A functional dependency FD: X → Y is called trivial if Y is a Subsetof X.
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Why are certain functional dependencies called trivial functional dependencies?
A functional Dependency_theory_(database_theory)(FD) is a constraint between two sets of attributes in a Relational_modelfrom a DatabaseGiven a relation R, a set of Attribute_(computing) X in R is said to functionally determineanother attribute Y, also in R, (written X → Y) if and only if each X value is associated with precisely one Y value. Customarily we call X the determinant set and Y the dependent attribute. Thus, given a Tupleand the values of the attributes in X, one can determine the corresponding value of the Y attribute. For the purposes of simplicity, given that X and Y are sets of attributes in R, X → Y denotes that X functionally determines each of the members of Y - in this case Yis known as the dependent set. Thus, a Candidate_keyis a minimal set of attributes that functionally determine all of the attributes in a relation.(Note: the "function" being discussed in "functional dependency" is the function of Identification_(information).)A functional dependency FD: X → Y is called trivial if Y is a Subsetof X.
What is functional dependency in computer terms?
Functional Dependencies A Functional Dependency describes a relationship between attributes in a single relation. An attribute is functionally dependant on another if we can use the value of one attribute to determine the value of another. Example: Employee_Name is functionally dependant on Social_Security_Number because Social_Security_Number can be used to determine the value of Employee_Name. We use the symbol -> to indicate a functional dependency. -> is read functionally determines Student_ID -> Student_Major Student_ID, Course#, Semester# -> Grade SKU -> Compact_Disk_Title, Artist Model, Options, Tax -> Car_Price Course_Number, Section -> Professor, Classroom, Number of Students The attributes listed on the left hand side of the -> are called determinants. One can read A -> B as, "A determines B".
What is it called when words only sound right in a certain order?
This phenomenon is known as word order dependency, where certain words or phrases are required to appear in a specific sequence for the sentence to make sense grammatically and semantically.
What is it called to have one functional kidney?
its called one functional kidney
Hwhat novelist called Shakespeare trivial and really bad?
Tolstoy
What is a nation called when it is governed by another nation?
Try "mandate". It could also be a colony, or it could be a protectorate, or could be simply an invaded country depending on the context.
What is the part of Antarctica called that New Zealand manages?
The Ross Dependency.
Archipelago to the north of Cuba that was formerly a British dependency is called what?
The Bahamas
When you use alcohol other drugs to function this is called?
Addiction or dependency.
What terms is defines as dependency on alcohol?
Traditionally, it has been called Alcoholism.
What are the non functional parts of the transcript called?
The non-functional parts of a transcript are called introns. They are the segments of RNA that are removed during mRNA processing, leaving only the functional segments called exons to be translated into proteins.
The archipelago to the north of cuba that was formerly a british dependency is called what?
The archipelago to the north of Cuba that was formerly a British dependency is called the Bahamas. A maquiladora is a foreign-owned factory in northern Mexico that assembles duty-free goods.
