Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
In a relation, tuples are not inserted in any definite order. Ordering of tuples is not defined as a part of a relation definition. Though, records may be structured later according to some attribute value in the storage systems. For instance, records in PERSON table may be structured according to PERSON_ID. Such organisation or data depends on the requirement of the underlying database application. Though, for the purpose of display we may get them displayed in the sorted order of age. The following table is sorted by age. It is also worth states here that relational model does not permit duplicate tuples
PERSON
PERSON_ID NAME AGE ADDRESS
2 Sharad Gupta 33 Pocket 2, Mayur Vihar.
1 Sanjay Prasad 35 b-4,Modi Nagar
3 Vibhu Datt 36 c-2, New Delhi
Super Keys, Candidate Keys and Primary Keys for the Relations
As discussed in the last section ordering of relations does not matter and all tuples in a relation are unique. Though, can we uniquely recognize a tuple in a relation? Let us talk about the concepts of keys that are primarily used for the purpose as above.
Which are the two ways in which entities can participate in a relationship? Total and partial are the two ways in which entities can participate in a relationship
Explain the concepts of relational data model? Relational Data Model - The relational model was first introduced through Prof. E.F. Codd of the IBM Research in the year 1970
why data in an RDMS need to be normalised
What is a dataset? A dataset is an in-memory database that is disconnected from any regular database, but has all the significant characteristics of a regular database. Dataset
Consider the join of a relation R with relation S. If R has m tuples and S has n tuples, then the maximum size of join is: If R has m tuples and S has n tuples then maximum siz
Extend your CREATE TABLE statement from problem 3 with referential integrity constraints. Updates and deletes on related rows are restricted. 6. From examination of the sample data
Part 1: Security Plan Consider the Case study and identify 3 security requirements. For each of these security requirements: • Discuss the necessity for the feature and how
What is catalog in DBMS? Catalog - A relational DBMS maintains information about every table and index in which it contains. A catalog is a collection of special tables that st
Your OS has a set of queues, each of which is protected by a lock. To enqueue or dequeue an item, a thread must hold the lock associated to the queue. You need to implement an a
Illustrate the view of software architecture A model is a semantically closed abstraction of system composes of elements. It can be visualized using any of the following five v
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd