Attributes and tuple, Database Management System

Assignment Help:

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


Related Discussions:- Attributes and tuple

Define hot swapping, Define hot swapping? Hot swapping permits the remo...

Define hot swapping? Hot swapping permits the removal of faulty disks and changes it by new ones without turning power off. Hot swapping decreases the mean time to repair.

Define the one-way associations, One-way Associations When an associat...

One-way Associations When an association is traversed only in the one direction, then it is implemented as a pointer i.e.an attribute which contains an object reference. If mu

Whenever the limit clause will be used, Whenever the LIMIT clause will be u...

Whenever the LIMIT clause will be used? LIMIT is used for the following kinds of problems: 1) Answering questions about first or last and largest or smallest 2) Splitting

What is a primary index, What is a primary index? A primary index is an...

What is a primary index? A primary index is an index whose search key also explains the sequential order of the file.

Benefits and drawbacks of sequential file organisation, Benefits of Sequent...

Benefits of Sequential File Organisation It is quick and efficient when dealing with huge volumes of data that require being processed periodically (batch system). Dra

Oracle RDBMS, compare the features of oracle RDBMS with MySQL and Microsoft...

compare the features of oracle RDBMS with MySQL and Microsoft SQL server

Entity identifier key attributes, An entity type usually has an attribute w...

An entity type usually has an attribute whose values are distinct for every individual entity in the collection. Such an attribute is known as a key attribute and its values can be

Database incident table, The Incident table, with an auto-incrementing in...

The Incident table, with an auto-incrementing incident number, etc, looks like: incident_num reporter date time incide

E-R Diagram, The H. I. Topi School of Business operates international busin...

The H. I. Topi School of Business operates international business programs in 10 locations throughout Europe. The school had its first class of graduates in 1965. The school keep

What are the disadvantages of relational data, What are the disadvantages o...

What are the disadvantages of relational data ? Disadvantages • Performance - If the number of tables among that relationships to be established are large and the tables t

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