Attributes and tuple, Database Management System

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

Posted Date: 3/6/2013 5:15:57 AM | Location : United States







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