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
why are older data models are being replaced by new data models
What are stand-alone procedures? Procedures that are not part of a package are called as stand-alone because they independently defined. A good example of a stand-alone procedu
Advantages And Drawbacks Of Ddbms There are various reasons for building distributed database systems, with sharing of data, reliability and availability, and speedup of query
define locking in simple language and decribed it
Mention various steps required to draw an E-R Diagram. Draw an E-R Diagram for Student Information System. Mention all suitable assumptions to justify your answer.
What is the need of a log in a DBMS? Briefly describe the various types of records that are normally present in a log. Ans: The system log, which is generally writt
What is Derived and stored Attribute? Derived and Stored Attribute - In a few cases, two or more attribute values are associated, for example, Age and BirthDate attributes of a
Data Manipulation Language Data manipulation language (DML) describes a set of commands that are used to query and change data within existing schema objects. In this case comm
For every multivalued attribute 'A', we make a new relation R that contains an attribute corresponding to plus the primary key attribute k of the relation that shows the entity typ
Determine the Derived attribute to avoid re-computation Each class box consists of an ordered list of attributes and operations, each represented as a next string. We can find
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