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
What is Management System? A management system is a set of rules and process which help us to create organize and manipulate the database. It also helps us to add, change delet
Benefits: It limits data access. It makes difficult queries look easy. It permits data independence. It presents dissimilar views of the similar data.
For the relations R and S given below: R S A B C 1 4 7 2 5 8 3 6 9
Which database object does not physically exist? A view database object does not physically exist.
Problem : AirwaysCentre, an international airline booking company currently uses a relational database system for their operations, which includes the following relations: P
What do you understand by RAID? Explain RAID Level 4 and Level5? RAID - It is stands for Redundant Array of Inexpensive Disks (as named by the inventor), or alternatively Re
What are the several kinds of the update operations on relations? Also explain the constraints on these update operation. Give instance in support of your answer. There are th
Explain the disadvantages of creating a temporary table? If you have already created a temporary table with a shown name and attempting to create a second one with that nam
what are the purposes of dbms in details
Consider the following relations: S (S#, SNAME, STATUS, CITY) SP (S#, P#, QTY) P (P#, PNAME, COLOR, WEIGHT, CITY) Give an expression within SQL for each of queries b
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