Advanced Database

Normalisation

Database normalization is the process of organizing the fields and tables of a relational database to minimize redundancy and dependency. Normalization usually involves dividing large tables into smaller (and less redundant) tables and defining relationships between them. The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database using the defined relationships.

UNF

Un-Normalised Form
Booking	(booking_ref_no, booking_date, student_no, student_name, student_address, student_telephone, course_code, course_name, course_level, start_date, finish_date, course_cost, lecturer_code, lecturer_name, lecturer_telephone, centre_name, centre_phone, class_size)

 

1NF

First Normal Form
Student 1	(student_no, student_name, student_address, student_telephone, course_code, course_name, course_level, start_date, finish_date, course_cost, lecturer_code, lecturer_name, lecturer_telephone, centre_name, centre_phone, class_size)
Booking 1	(booking_ref_no, booking_date, student_no)

2NF

Second Normal Form
Booking 2	(booking_ref_no, booking_date, student_no)
Student 2	(student_no, student_name, student_address, student_telephone, course_code)
Course 2	(course_code, course_name, course_level, start_date, finish_date, course_cost, centre_name, centre_phone, class_size, lecturer_code)
Lecturer 2	(lecturer_code, lecturer_name, lecturer_telephone)

3NF

Third Normal Form
Booking 3	(booking_ref_no, booking_date, student_no)
Student 3	(student_no, student_name, student_address, student_telephone, course_code)
Course 3	(course_code, course_name, course_level, start_date, finish_date, course_cost, centre_code)
Lecturer 3	(lecturer_code, lecturer_name, lecturer_telephone)
Centre 3	(centre_code, centre_name, centre_phone)
Class 3	(centre_code, class_size)

E-R Model

Data Dictionary

Generation of Database  
 DDL generated by the server model:  
 -- E:\anitsql\anit2.tab  
 ---- Generated for Oracle 9i on Mon May 13 11:24:30 2013 by Server Generator 10.1.2.6.18  
  PROMPT Creating Table 'COURSES'  
 CREATE TABLE COURSES  
  (COURSE_LEVEL VARCHAR2(15)  
  ,FINISH_DATE VARCHAR2(240)  
  ,START_DATE VARCHAR2(240)  
  ,COURSE_NAME VARCHAR2(25)  
  ,COURSE_CODE INTEGER NOT NULL  
  ,COURSE_COST INTEGER  
  )  
 /  
 PROMPT Creating Table 'BOOKINGS_COURSES'  
 CREATE TABLE BOOKINGS_COURSES  
  (COU_COURSE_CODE INTEGER NOT NULL  
  ,BOO_BOOKING_REF_NO INTEGER NOT NULL  
  )  
 /  
 PROMPT Creating Table 'LECTURERS'  
 CREATE TABLE LECTURERS  
  (LECTURE_TELEPHONE VARCHAR2(10)  
  ,LECTURE_NAME VARCHAR2(25)  
  ,LECTURE_CODE INTEGER NOT NULL  
  )  
 /  
 PROMPT Creating Table 'COURSES_LECTURERS'  
 CREATE TABLE COURSES_LECTURERS  
  (LECT_LECTURE_CODE INTEGER NOT NULL  
  ,COU_COURSE_CODE INTEGER NOT NULL  
  )  
 /  
 PROMPT Creating Table 'COURSES_STUDENTS'  
 CREATE TABLE COURSES_STUDENTS  
  (STUD_STUDENT_NO INTEGER NOT NULL  
  ,COU_COURSE_CODE INTEGER NOT NULL  
  )  
 /  
 PROMPT Creating Table 'CENTERS'  
 CREATE TABLE CENTERS  
  (CENTER_NAME VARCHAR2(25)  
  ,CENTER_CODE INTEGER NOT NULL  
  ,CENTER_TELEPHONE VARCHAR2(10)  
  )  
 /  
 PROMPT Creating Table 'BOOKINGS'  
 CREATE TABLE BOOKINGS  
  (BOOKING_REF_NO INTEGER NOT NULL  
  ,BOOKING_DATE VARCHAR2(240)  
  ,STUD_STUDENT_NO INTEGER  
  )  
 /  
 PROMPT Creating Table 'STUDENTS'  
 CREATE TABLE STUDENTS  
  (STUDENT_NAME VARCHAR2(25)  
  ,STUDENT_TELEPHONE VARCHAR2(10)  
  ,STUDENT_NO INTEGER NOT NULL  
  ,STUDENT_ADDRESS VARCHAR2(30)  
  )  
 /  
 PROMPT Creating Table 'CENTERS_COURSES'  
 CREATE TABLE CENTERS_COURSES  
  (COU_COURSE_CODE INTEGER NOT NULL  
  ,CEN_CENTER_CODE INTEGER NOT NULL  
  )  
 /  
 PROMPT Creating Table 'LECTURERS_STUDENTS'  
 CREATE TABLE LECTURERS_STUDENTS  
  (STUD_STUDENT_NO INTEGER NOT NULL  
  ,LECT_LECTURE_CODE INTEGER NOT NULL  
  )  
 /  
 PROMPT Creating Table 'CLASSES'  
 CREATE TABLE CLASSES  
  (CLASS_SIZE INTEGER  
  ,CENTER_CODE INTEGER NOT NULL  
  ,CEN_CENTER_CODE INTEGER NOT NULL  
  )  

Data insert using SQLPlus:

Data Flow Diagram

Functional Hierarchy Diagram

Process Modeller Diagram

Further Discussion

From the last 30 years. There are a number of the newer techniques available in our experience though even the technology has changed dramatically. While developing requirements for an interactive system, we initially need to discover and report: the overall process-flow, the activities being performed, the inputs & outputs to the activities, the event that trigger the activities, who performed the activities, where the activities are performed, where information is stored, who supplies the information & who needs to receive the information. Likewise we need to assess all these things and specify them in a set of new business process requirements.

Data Flow Approach

Using the data flow approach has a lot of advantage, especially for data driven applications where processing requirements are beyond the computational power. Data flow diagrams are the one of the main methods available for analysing data-oriented systems. Through the uses of data flow emphasizes the logic underlying the systems; the systems analysts can put together a graphical representation of data movement through the organization. For the LONDON METROPOLITAN COLLEGE “Student Management System” data flow diagram helps to maintain the analysis proposed system to determine if all the data and processes have been defined. By the incorporation of different levels the DFD can provide the view of the whole London metropolitan university overall activities relating the students management. Also this data flow approach help to find the boundary of the college administrative tasks. Finally it also helps to generate the information from the view point of data movements, which includes the inputs and outputs to which students can readily relate. The main advantages are

·         It is the part of the system documentation file

·         Straightforward graphical technique which is easy to recognise

·         It supports the logic behind the data flow within the system.

The disadvantages are

·         Physical considerations are left out

·         Make programmer little confusing concerning the system.

·         It takes long time to create, so long that the analyst may not receive support from management to complete it.

Process Diagram Approach

The process diagram provides a visual representation of the steps in a process. Flow charts are referred to as process mapping or flow diagrams. There are various benefits of using process diagram such as

·         Make process flowcharts

·         Give everyone a clear understanding

·         help to identify non value added operations

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No service

No service? Maybe you've been zapped by a cell phone jammer.

[More from Mashable: FCC: Cybersecurity Is Crucial for America’s Future]

A Philadelphia man has stirred up controversy after he frequently used a device on a public bus to create a cell phone dead zone.

A reporter for NBC10 in Philadelphia recently tracked down the man, who was using a cell phone jammer on the bus to block riders' cell phone reception. His reason — he didn't want to listen to other people's phone conversations. He says he turns on the illegal device whenever other passengers talk too loud and bother him.

[More from Mashable: Everything You Need to Know About Wireless Spectrum [INFOGRAPHIC]]

The man, identified as Eric, told NBC reporters: “I guess I’m taking the law into my own hands, and quite frankly, I’m proud of it.”

A jammer typically looks similar to a walkie-talkie and has multiple antennae pointing out of the top of the device. Its job is to jam, block or interfere with wireless communication including Wi-Fi, cell phone reception, GPS and police radar.

Section 302(b) of the Communication Act of 1934 [PDF] prohibits the "marketing, sale or use" of jammers. The federal government and companies contracted to do federal work, typically related to homeland security, are the only ones permitted to use jammers. Like many uninformed people who have jammers, Eric said he thought a jammer was legal to use.

"We are troubled by the reported incident and are looking into it," Michelle Ellison, Chief of the Federal Communication Commission Enforcement Bureau, said in an email regarding the Philadelphia incident.

Although the device is illegal, bus riders aren't the only ones who have wanted to shut people up using a jammer. The FCC has investigated the use of cell phone jammers in schools and theaters. Some administrators apparently think a cell phone jammer would be an easy way to stop students from using their cell phones during school hours. Theaters find cell phone jammers appealing to prevent people from using phones during shows.

"While some people who use jammers may think they are only silencing loud conversations or disabling unwanted GPS tracking, they could also be preventing a scared teenager from calling 911, an elderly person from placing an urgent call to a doctor, or a rescue team from homing in on the location of a severely injured person," Ellison said. "The price for one person's moment of peace or privacy, could very well be the safety and well-being of others."

Jammers are a problem because they block licensing frequencies that are not owned by the jammer and it's illegal to interfere with any licensing frequency. Jammers can block signals within a few dozen to hundreds of feet. The FCC is most concerned with jammers blocking emergency responders communication with callers.

People in the U.S. typical buy jammers online. The FCC is trying hard to prevent other countries from selling and shipping jammers to America, but some jammers slip through the mail. Th UK, Canada, Switzerland and Australia also don't allow cell phone jammers.

In October 2011, the FCC warned 20 online retailers about the illegality of selling and marketing signal jamming devices to Americans. But, with a quick Google search away, an American can order a cell phone jammer online.

"Our actions should send a strong message to retailers of signal jamming devices in the U.S. is illegal and that the FCC will vigorously prosecute these violations," Ellison said in a press release.

The U.S. tries hard to keep jammers out, but, the network blockers can be manufactured and exported in the U.S. The FCC said it isn't aware of any cell phone jammer manufacturing violations in the U.S. Do you think cell phone jammers should be legal? Tell us in the comments below.

Photo courtesy of iStock, leminuit

This story originally published on Mashable here.

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New Year 2012

       I am an optimist and believe we will be here to celebrate a New Year in January 2013. I believe that not only will we survive but we will see a new beginning with the passing of the age. Nevertheless we cannot be complacent; we cannot just assume that "the best is yet to come." Humans have intervened in the natural order too much and humans have to recognize the repercussions of our disturbance and make necessary changes for our survival. We have to do our part to change old ways to new ways.

Just a partial list of the challenges I enumerate in the book include:
• Global warming and climate change, melting ice caps, endangered species
• Increasing incidents of extreme weather, such as hurricanes, tornadoes, drought, floods, and tsunamis
• Increasing incidents and severity of earthquakes and volcanic eruptions, and other earth changes
• The energy crisis of impending fossil fuel shortages, and inadequate and delayed development of alternative fuels
• International terrorism combined with religious fanaticism, the spread of powerful weapons that can be triggered by individuals and small groups and the collapse of democratic governments
• The reappearance of nationalist expansionism and tribal/ethnic conflicts causing extensive suffering and death to minority populations
• The seeming renewal of the "Cold War" between resurgent Russia and the over-extended United States with a near helpless Europe in the middle
• A very real arms race, with arms producers again selling weaponry to all comers
• The existence of, and newly emerging threats of, nuclear blackmail
• The appearance and spread of new diseases through rapid migration of people and importation of animal and vegetable products beyond their natural habitat
• The potential danger of dependence on newly deployed technology without redundancy for backup and shortages of trained personnel
• A failing educational system not providing even basic skills for the Information Age, for a technology based economy and a global society
• A crumbling infrastructure of transportation, utilities, communications and public safety
• The loss of ethical, moral and spiritual pertinence to guide individual & institutional behavior
• The lack of true international law and enforceable justice system
• The growth of piracy—on the high seas, on the Internet, and in the market place through non-compliance with copyright and trademark laws, evasions of patent protection, and blatant theft of intellectual property
• An inability to develop a supportive, non-punitive, tax system
• The lack of meaningful and pertinent political debate
• A failed, fiscally irresponsible government administered by ideologues and special interests
• The failure of democratic and parliamentary governments to address the fundamental needs of their constituencies rather than pandering to superficialities and special interests
• A worldwide lack of sufficient investment in new technologies and basic science

The list could go on and on. It’s like the drumbeat of disaster, the sound of a failing heart or the whine of an incoming missile. 

                                                                                     -By: Dr.Joe (Psychic Empowerment for everyone).

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I AM PROUD TO BE COMMUNIST

Camila Vallejo: Proud of Being Communist

The Chilean student leader doesn't mince her words.

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Journey to the Intimate "

 ... I rode the steed of thought,
 went through long tunnels of memory,
 pretending to know me again ...
 ......
 - There were olive trees, ancient temples,
 gutted by relentless time.
 They looked like ghosts, resistant
 where I gathered the moss of my inner past.
 D'lush paths walked past,
 fruity myrtle, flowering rosemary.
 There was also a pungent odor,
 intoxicating, the mimosa jasmine flower.

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Wake Up

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Some movies just not for the squeamish

“127 Hours” has earned glowing reviews as well as six Academy Award nominations, including Best Picture and Best Actor for star James Franco. The film’s artistic merit has stirred little debate, but “127 Hours” may be suffering from the “Not For The Squeamish” syndrome, which afflicts certain motion pictures that contain scenes guaranteed to at least make you squirm.

The Danny Boyle-directed drama is based on the true story of Aron Ralston, who falls into a crevice while on a hike, has his arm pinned by a large rock and eventually has to cut it off in order to survive.

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