• Keine Ergebnisse gefunden

A relational model of data for large shared data banks

N/A
N/A
Protected

Academic year: 2022

Aktie "A relational model of data for large shared data banks"

Copied!
1
0
0

Wird geladen.... (Jetzt Volltext ansehen)

Volltext

(1)

A relational model of data for large shared data banks E. F. Codd. Communications of the ACM. 1970

Questions

Alexander

1. What is the problem that Codd tries to solve? What was the state of data base system up to that point and why was that a problem?

2. What are the possible disadvantages of the proposed solution?

3. Codd's solution is widely adapted in modern DBS. Which parts are implemented, which have changed since, and which ones were never implemented?

Stefan

1. What is normalization (in the context of databases), how is it carried out and what are its advantages?

2. What is the difference between strong and weak redundancy and how are they avoidable?

3. Which operations on relations are presented in this paper?

Vasker

1. Describe shortly the relational data model and it's concepts.

2. What are the two proposed features of a universal data sublanguge?

3. Show two relations are composable if and only if they are joinable.

Referenzen

ÄHNLICHE DOKUMENTE

We present a novel sampling-based approximation technique for classical multidimensional scaling that yields an extremely fast layout algorithm suitable even for very large graphs..

In case the reproduction or provision of data is complex (in time and/or resources), factors such as data volume, frequency of data access and data changes, or the speed of

In order to state the privacy problem, we employ the notion of certain answer: data privacy is preserved for a query with respect to the provided public knowledge if there are

For privacy-preserving information sharing for data analysis, we consider a mechanism that consists of the data holders, the data analyzer, the activator, the private-key holder,

Views or opinions expressed herein are those of the author and should not be interpreted as representing the view of either the Institute or the National Member

A simple descriptive model is proposed for the analysis of large, non-additive mortal- ity arrays. Similar in form to additive-plus-multiplicative models discussed by

A large number of novel information visualization techniques have been developed over the past decade, allowing visualizations of ever larger and more com- plex, or

In this article, we describe an overview of methods for visualizing large spatial data sets containing point, line and area phenomena.... The results show that the visualization