Ordering of tuples, Database Management System

Assignment Help:

In a relation, tuples are not inserted in any definite order. Ordering of tuples is not defined as a part of a relation definition. Though, records may be structured later according to some attribute value in the storage systems. For instance, records in PERSON table may be structured according to PERSON_ID. Such organisation or data depends on the requirement of the underlying database application. Though, for the purpose of display we may get them displayed in the sorted order of age. The following table is sorted by age. It is also worth states here that relational model does not permit duplicate tuples

PERSON

PERSON_ID      NAME                                 AGE              ADDRESS

2                           Sharad Gupta                       33                  Pocket 2, Mayur Vihar.

1                           Sanjay Prasad                      35                  b-4,Modi Nagar

3                           Vibhu Datt                           36                  c-2, New Delhi

Super Keys, Candidate Keys and Primary Keys for the Relations

As discussed in the last section ordering of relations does not matter and all tuples in a relation are unique. Though, can we uniquely recognize a tuple in a relation? Let us talk about the concepts of keys that are primarily used for the purpose as above.


Related Discussions:- Ordering of tuples

Explain about data independence, Data Independence This brings us to ou...

Data Independence This brings us to our next topic: data independence. It is the property of the database which tries to make sure that if we make any change in any level of sc

Explain outer join, Explain outer join? Outer Join - If there are any...

Explain outer join? Outer Join - If there are any values in one table which do not have corresponding value(s) in the other, in an equi-join which will not be chosen. Such ro

Creating views with read only option-data control, Creating views with Read...

Creating views with Read only option : In the view definition this option is used to make sure that no DML operations can be done on the view.

Record based logical models, Record based Logical Models: Use records as th...

Record based Logical Models: Use records as the key data representation components Examples: Relational Model: It shows data as well as relationship between data in the form

3NF Normalization, Need 2 projects completed in 3NF format.

Need 2 projects completed in 3NF format.

Cube building in dataware housing , 1) Define a job scheduling strategy tha...

1) Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pict

Explain the two constraints check and foreign key in sql, Explain the two c...

Explain the two constraints, check and foreign key in SQL along with an example for each. Give the syntax. CHECK constraint - CHECK constraint specifies an expression which

What are the concurrency issues, Concurrency issues Data integrity...

Concurrency issues Data integrity: Threads accessing same object need to be synchronized, such as: banking account. Deadlock: One or more threads in system are perman

Explain the functions of data manager, Explain the functions of data manage...

Explain the functions of data manager? Functions of Data Manager : - Convert operations in user's queries coming directly through query processor or indirectly in an applicatio

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