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2answers
115 views

PostgreSQL : dependencies on a schema

I need to delete a schema in my PostgreSQL database. I would like to make sure that the schema is not used in another schema (for instance : this schema is used for a view in another one). Is there a ...
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1answer
12 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 ...
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0answers
14 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 ...
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0answers
61 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
27 views

Decompose table into third normal form

Tables X and Y are given as below : X (A, B, D, E, F, G, H, J) with A and B as primary key Y (K, L, M, N, O, P, Q, R) with K and L as primary key Now we need to decompose these tables into tables ...
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15 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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0answers
50 views

identifying the functional dependencies

I have been reading up on database design and I am having some difficulty constructing functional dependency diagrams from tables. I have the following table. Each salesperson is identified by a ...
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0answers
39 views

calculating Canonical covers

Given F = {AB -> C, A -> BC, B-> A}, compute Fc AB-> C is A extra? {B->C, A-> BC, B->A} 1st possible Fc = {A->BC, B->AC} AB-> C is B extra? {A->C, A->BC, B->A) 2nd possible Fc = {A->BC, ...
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71 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 ...