HL+Case+Study

=ITGS HL Case Study Resources=

[[file:2012_d_3_itgsx_css_1205_1_e.pdf]]
** Theatre Booking System - Quizlet Flashcards** **Case Study 2012 Online resources from the ITGS Textbook - MUST READ **

**IMPORTANT!!** ** Update on the NEW ITGS Guide Paper 3 **
 * There will be FOUR questions on Paper 3 in May 2012
 * The questions are related to the scenario in the case study
 * Q1 and Q2 may be sub-divided (in parts)
 * Q3 is assessed using this markband (max marks = 8) - [[file:Rubric for extended Qs HL_SL_Specimen papers_2012_d_3_itgsx_spp_1004_2_e-2.pdf]]
 * Q4 is assessed using this markband (max. marks = 12) - Note, there must be independent research and investigation for students to reach the top level - [[file:CaseStudy_Q4_Markband.pdf]]

**EVEN NEWER!!** ** Specimen Paper for new ITGS Guide ** Case Study **'N&Q Investments'** - Paper 3 Questions - Paper 3 Markscheme - coming

**NEW!! Past Case Study for review** This Case Study from Nov 2011, **'Developing and Running an Online Business'** gives some insight into how a Paper 3 is constructed. Scenario: Questions:

TASK 1
PDF information file from IB - Review the attached file in class and highlight: one colour for technical terms (blue), issues (yellow), stakeholder (green), general vocabulary (red).

HL 2012 CS GLOSSARY

TASK 2
Theatre Booking System wiki for collaboration - explore all aspects of the wiki and come to class with recommendations

TASK 3
Read this blog post about the Case Study. Let's discuss in class before you answer questions.

Generic Case Study Questions:
Define centralised database. A centralized database is a database where all information of a organization is stored at one location such as a mainframe computer or server. Users can access the database through WAN (Wide Area Network) using software applications.

Define distributed database. What are the advantages/disadvantages. In a distributed database, information is stored in multiple and various devices/computers/servers in multiple physical locations.

Define DBMS. Database management system is a collection of programs that enables you to store, modify, and extract information from a database.

Examine the diagrams and look at the research and notes posted in the wikispace. Does each model (centralised, decentralised and distributed) require the same hardware, DBMS and operating system? All models of database (centralised, decentralised and distributed) require a DBMS (Database Management System) for organization, storage, and retrieval of data. Centralised databases require a mainframe server or computer to store/access/modify a database stored in one physical location, users access this data through the wide area network. In a distributed database, there are many database storages in multiple locations and different servers. They are then joint using a central Database Management System (DBMS) allowing users to access different servers. In a decentralized database, individual databases are stored separately and not connected through a mainframe server or Database Management System (DBMS) but instead has its own independent DBMS. These are more individual private client based databases allowing access from only one site.

What are the networking requirements for users to access the data for each model? 1. centralised, 2. decentralised, 3. distributed? 1. In a centralised database, the user needs a connection to the local Wide Area Network and sometimes the World Wide Web to access the site containing the DBMS for the specified database. 2. In a decentralised database, the user needs a local connection to the server to access the database, or sometimes a connection to the local area network. Note that a internet connection is not always required. 3. In a distributed database, the user needs a Wide Area Network Connection, most commonly with internet to access the server and DBMS in order to store/access/modify one of the many specified databases (On the server the user wants).

What is a VPN? Which models would require a VPN and for what purposes? VPN stands for Virtual Private Network, it offers a secure client to server connection bypassing firewalls or any other server filters. Generally all database models may require a VPN connection if database access is restricted due to the local firewall. But generally a VPN will only be required for distributed and centralized databases as the decentralized database requires a connection to the local server and may not require internet connection.


 * 1) Review the ACID: Atomicity, Consistency, Isolation, Durabilty.
 * 2) Discuss the advantages of having a centralised db system over DDBMS (Your response should review some of the aspects of the ACID model).
 * 3) Discuss the advantages of having a DDBMS over a centralised db (Your response should review some of the aspects of the ACID model).

Questions relating to the case study:

 * 1) Assume you are worked for CT at Site 1 (the first small theatre). How many locations can the same data be stored and accessed from in for each of the three configurations?
 * 2) What happens if two customers want to book the same seats at the same time at (site 1) CT for each of the three configurations?
 * 3) What are the advantages for (site 1) CT for staying as they are – ie their own database system? (diagram 3)
 * 4) What are the advantages for (site 2) MTG for staying as they are? (See diagram 3)
 * 5) Would a centralised system (site) be better for CT? (see diagram 1, the database is stored in one place at site, and not at site 1, CT)
 * 6) Would a centralised system be better for MTG? (likewise, see diagram 1)
 * 7) Would a distributed db system be better for (site 1) CT and (site 2) MTG? See diagram 2, the data for CT is stored on a server at CT (site 1) however users can also access data for other theatre companies in the PTC, for example site 2 and others.
 * 8) Overall, in your opinion and based on the case study and the points discussed above, what system should PTC adopt?

Resources: Questions obtained from @http://www.insideitgs.net/2012/01/28/case-study-2012-tech-focus-centralised-vs-distributed-databases/