Questions tagged [database-theory]

the analytic study of ways in which information is efficiently and effectively stored to and retrieved from computer systems.

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Does 1NF require that there can be no duplicate rows?

From Database System Concepts, by Silberschatz, Korth and Sudarshan : A domain is atomic if elements of the domain are considered to be indivisible units. We say that a relation schema ...
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Does 2NF require 1NF?

From Database System Concepts, by Silberschatz, Korth and Sudarshan : A domain is atomic if elements of the domain are considered to be indivisible units. We say that a relation schema ...
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6answers
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What use are groups, monoids, and rings in database computations?

Why would a company like Twitter be interested in algebraic concepts like groups, monoids and rings? See their repository at github:twitter/algebird. All I could find is: Implementations of ...
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When should you use the existential and universal quantifiers for Relational Calculus?

Could someone explain to me WHEN do you use existential and universal quantifiers for Relational Calculus? Given this schema: Hotel(hotelNo, hotelName, city) ...
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1answer
568 views

How to evaluate relations in a DAG?

To begin with: what I know of computer science is what friends have told me and what I've read on Wikipedia. Please correct me if I'm using some term wrongly, or if there is something I can clarify. ...
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2answers
554 views

Which is more fundamental: key-value or subject-predicate-object?

There seems to be two approaches to store data in NoSQL databases: Key-Value - The Key is usually stored in a hash-table referencing a ...