Tutorial 5- 7th OCT 2013

Database ACID (Atomicity, Consistency, Isolation, Durability)

There are a set of properties that guarantee that database transactions are processed reliably, referred to as ACID (Atomicity, Consistency, Isolation, Durability).
ACID

Atomicity

Atomicity refers to the ability of the database to guarantee that either all of the tasks of a transaction are performed or none of them are.

Consistency

The consistency property ensures that the database remains in a consistent state before the start of the transaction and after the transaction is over.  For example, in a storefront there is an inconsistent view of what is truly available for purchase if inventory is allowed to fall below 0, making it impossible to provide more than an intent to complete a transaction at checkout time.


Isolation

Isolation refers to the requirement that other operations cannot access or see the data in an intermediate state during a transaction. This constraint is required to maintain the performance as well as the consistency between transactions in a database.

Durability

Durability refers to the guarantee that once the user has been notified of success, the transaction will persist, and not be undone. This means it will survive system failure, and that the database system has checked the integrity constraints and won't need to abort the transaction. Many databases implement durability by writing all transactions into a transaction log that can be played back to recreate the system state right before a failure.


B) Podcast website.
      http://www.npr.org/rss/podcast/podcast_directory.php

  C) IMBD.com
       

        Kick ass 2
       http://www.imdb.com/title/tt1650554/

       

           
       Despicable me
       http://www.imdb.com/title/tt1323594/
  
            

       Atlantic Rim
       http://www.imdb.com/title/tt2740710/

                             
       Fast and Furious 6
       http://www.imdb.com/title/tt1905041/

                                

       The Day the Earth stood still
       http://www.imdb.com/title/tt0970416/

C.How visitors can query the movie database.

     Customers can search their movie using the search bar that is provided in the website. Customer can also choose search based on keywords like titles, TV Episodes, Names, Companies, Character, Keywords, Videos, Quotes, Bios, Plots that make it easier for customer to search for their favourite movie.

Customers can also search the movies using categrory that are provided below the search bar.

Is divided into categories like MOVIES, CHARTS AND THRENDS, SPECIAL FEATURES AND  TV & VIDEOS so that customers can get the latest movies and their favourite movies just in one click.