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

In an e-r diagram how attributes are represented, In an E-R diagram how att...

In an E-R diagram how attributes are represented ? In an E-R diagram attributes are represented in a ellipse.

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

How to define a structure with tag name car_table, QUESTION (a) Conside...

QUESTION (a) Consider a car database consisting of car model, car make, car origin, Engine capacity, color, cost.

Define rule that value of foreign key appear in other table, Determine the ...

Determine the rule that a value of a foreign key should appear as a value of some particular table is called a  Ans: Referential constraint.    The rule that a value of a fo

Explain interblock gap, Explain Interblock gap? Interblock Gap - A trac...

Explain Interblock gap? Interblock Gap - A track of a disk is separated into equal-sized disk blocks. Blocks are separated through fixed-size gaps, called as interblock gaps th

The sap profile parameter, While sorting, if the main storage available is ...

While sorting, if the main storage available is not enough, the system writes data to an external help file.  The SAP profile parameter, which determines DIR_SORTTMP

Define the terms key attribute and value set, Define the terms i) Key attr...

Define the terms i) Key attribute ii) Value set Key attribute: An entity type usually has an attribute whose values are exact from each individual entity in the collection. Su

Decomposition, properties of derirable decomposition

properties of derirable decomposition

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