Database Joins, Network Types, and Distributed Design

Posted by on Feb 17, 2025 in Information Systems Engineering | 0 comments

Database Joins

A join is derived from the Cartesian product. There are various forms of joins:

0-JOIN

It is an equi-join of two relations R and S over an attribute (or attributes).

NATURAL JOIN

In an outer join, tuples exist in the result relation regardless.

OUTER JOIN

Defined over the set of attributes A, by relation S, defined over the set.

SEMIJOIN

Decreases the number of tuples that need to be handled to form the join.

Advantage of SEMIJOIN

RELATIONAL CALCULUS

Specifies the properties that the result should

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Distributed Database Design & Cloud Computing Fundamentals

Posted by on Jan 17, 2025 in Information Systems Engineering | 0 comments

Distributed Database Design

Top-Down Distribution Design

This design method starts from a general overview and moves to specifics.

Bottom-Up Distribution Design

This design is presented when the databases already exist.

First Part of a Framework

Requirement analysis and view design.

Degree of Fragmentation

This goes from one extreme that is not the degree of fragmentation.

Approaches for Developing any DDBS

Two approaches for developing any DDBS appear: Top-Down and Bottom-Up.

Dividing Horizontally or Vertically

Relation

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