Super keys, Database Management System

Assignment Help:

A super key is an attribute or set of attributes used to recognize the records uniquely in a relation.

For instance, in the Relation PERSON defines earlier PERSON_ID is a super key since PERSON_ID is unique for every person. Likewise (PERSON_ID, AGE) and (PERSON_ID, NAME) are also super keys of the relation PERSON as their combination is also unique for each record.


Related Discussions:- Super keys

Draw an e-r diagram and convert it to a relational schema, In an organizati...

In an organization several projects are undertaken. Each project can employ one or more employees. Each employee can work on one or more projects. Each project is undertaken on the

State the component diagram, State the Component Diagram A component d...

State the Component Diagram A component diagram represents a set of component and relationships among them. In a dynamic model, component diagram is used to model physical com

What are the disadvantages of file processing system, What are the disadvan...

What are the disadvantages of file processing system? The drawbacks of file processing systems are a) Data redundancy and inconsistency b) Complexity in accessing data

Objectives-distributed and client server databases, Objectives diff...

Objectives differentiate DDBMS and conventional DBMS; Describe Network topology for DDBMS; Describe the concepts of horizontal and vertical fragmentation; Descr

Primary interface between a visual basic application, Question (a) Visu...

Question (a) Visual Basic is governed by an event processor. Explain the meaning of this phrase. (b) Differentiate between an general procedure and event procedure. (c)

What is data model explain object and data base models, What is data model?...

What is data model? Explain object based and record based data models? Ans: A data model is an abstract model in which describes how data is represented and accessed. (i)

Create the database in oracle using ddl, The Assessment page has a link to ...

The Assessment page has a link to download a conceptual model, and a list of data. You are to map this conceptual model, and create the database in Oracle using your own DDL.  T

Explain difference between volatile, Explain the difference between the thr...

Explain the difference between the three storage types - volatile, non volatile and stable.             Ans: Volatile storage: if storage media loses data while power goes off,

Strong entity set and weak entity set, Strong entity set and weak entity se...

Strong entity set and weak entity set? Strong entity set and weak entity set: A strong entity set has a primary key. All tuples in the set are distinguishable through that key.

What are referential integrity constraints, What are referential integrity ...

What are referential integrity constraints? A value that appears in single relation for a given set of attributes also appears for a particular set of attributes in another rel

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd