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!
Before we talk about the relational model in more detail, let us first define some very basic terms used in this model.
Tuple
Every row in a table shows a record and is called a tuple. A table containing 'n' attributes in a record is called n-tuple.
Attribute
The name of every column in a table is used to interpret its meaning and is known as an attribute. Every table is called a relation.
For instance, Figure shows a relation PERSON. The columns NAME, PERSON_ID, AGE and ADDRESS are the attributes of PERSON and every row in the table represents a separate tuple (record).
Relation Name: PERSON
PERSON_ID
NAME
AGE
ADDRESS
TELEPHONE
1
Sanjay Prasad
35
b-4,Modi Nagar
011-25347527
2
Sharad Gupta
30
Pocket 2, Mayur Vihar.
023-12245678
3
Vibhu Datt
36
c-2, New Delhi
033-1601138
Figure: An extended PERSON relation
Give the limitations of SQL authorization. The code for checking authorization becomes intermixed with the rest of the application code. Implementing authorization by applic
Describe relational model? Structure of relational data base Basic structure Database schema Keys Schema diagram Query languages
Explain mechanism of nested queries? SQL gives a mechanism for nesting subqueries. A subquery is a select from where expression that is nested within one more query. A common u
what is primary key
How to design a formal and exact model How to design a formal and exact model of real-world problems by applying findings of analysis phase of OMT. The object design phase find
differences between a classified catalog and a dictionary catalog
Complete replication: It implies maintaining of a whole copy of the database at every site. Thus, the reliability & availability and performance for query response are maximized.
QUESTION (a)(i) Define the term database. (ii) How is it different from a database management system? (b) What is the difference between an entity and an attribute? (c
Northwind Pty Ltd sells a variety of food products throughout the world. They want to use the reporting features of SAP''s Business Information Warehouse to better understand thei
multiplicity constarin
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