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1answer
26 views

Determining Transitive Dependencies

I am working on figuring out partial and transitive dependencies. The Transitive ones are really confusing me because I can see a transitive dependency on nearly all of these. The partial ...
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1answer
34 views

Determining Functional and Transitive dependencies from Relational Model (with no sample data)

I have a relational model which I've converted from an EER diagram... I've been asked to find the functional and transitive dependencies but how does one do that when there's no sample data to start ...
2
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19 views

Decomposition and loss of dependencies

I'm lost in the sea with the following example of decomposition without loss of dependencies... Let be the dependencies F= {A → BC, C → AD} R is decomposed in R¹(A,B,C) & R²(A,D) I want to know ...
2
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0answers
97 views

Is the table in 3NF?

I am creating a relational database - a library management system. I want to show an example where I normalize the data from 2NF to 3NF. My example of 2NF looks like The definition of third normal ...
2
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0answers
195 views

Identifying functional dependencies

I'm having trouble understanding the logic in use for identifying functional dependancies. Looking at the sample relation below, I understand fd1 - fd3. But when I look at fd4 and fd5, its logic ...
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0answers
55 views

testing an extraneous attribute in a relation using functional dependency

I am studying the book "Database System Concepts" by sudarshan . In chapter 8.4.3 in a dependency alpha->beta , If A ∈ aplha to check if A is extraneous, let (gamma = alpha − { A}), and check if ...
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186 views

SQLServer dependency graph and performance

I have a large stored procedure running on SQLServer2008 to produce a report on the previous day's data. It rehashes data from 12 tables, including a lot of ORDER by date and CASTS. Among others, it ...
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0answers
11 views

Example of dependencies preserved in decomposition

Let be the follwing relation Car(NV,Marque, Type, Puissance, Couleur) With the following dependencies: Why does this decomposition preserves Functional dependencies R1(NV,Type, Couleur) R2(Type, ...
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15 views

Algorithm of decomposition in Boyce-Codd Normal Form

I have to give the keys of the following relation, say if they are 1,2 or 3NF and give a BCNF decomposition. Yet I think I misunderstand the difference between 2NF and 3NF: R(A,B,C,D,E) with ...
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0answers
11 views

Determining decomposition without loss of dependencies

Let be the following relational scheme: R(A,B,C,D,E,F,G) and a family of functional dependencies. F={AB→C;AC→B;AD→E;B→D;BC→A;E→G} Is following decomposition without loss of dependencies? ...
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8 views

Redundancy and lossless relation

Let be R (Course, Student, DateOfBirth, Grade) provided with the following family of functional dependencies: F={C,S→G, E→DoB} The relation is splited up in two by R1(C,S,G) and R2(S,DoB). ...
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73 views

Exam question about BCNF

I am trying to unravel the following question about BCNF from a past exam paper that is available online. The question, which is on page 7 of the linked PDF, says: Suppose that R(A,B,C,D) is a ...
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17 views

Determining the 3NF based on functional dependencies

Given a relation R = {E M L T} and functional dependancies LT -> E, ET -> L, TM -> E, and E -> M , I know that the superkeys of this relation is TL, TE, and TM. For 3NF, the left hand dependancies ...
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24 views

Managing View Dependencies

I am using PostgreSQL and I am adding a single column to a view. Unfortunately, I will have to drop and recreate that view as well as the 9 other views that are dependant on the view. What ...
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Object dependencies of stored procedure in SQL Server 2008

I need to have object dependencies of stored procedure in same sequence that objects are called in the procedure Can we export these dependencies to an Excel file?