Add Headings and they will appear in your table of contents.
A.3.1 Explain the roles of a Database Administrator (DBA)
Roles/Tasks of a DBA:
Responsible for installing and configuring the hardware and software that will manage the database.
Responsible in creating the database schema, Entity-Relationship Diagram (ERD) and relationships between tables.
Create the database objects like database file, tables, fields, queries, forms and reports. Update them when needed.
Responsible for planning and executing data migration with backup recovery plans for data loss.
Set up user accounts who will use the database and set up permission/access rights (view, edit, delete).
Conducting user training on how to use the database.
Making sure that the database is secured from hacking and viruses by installing anti-hacking and anti-virus software.
Responsible for regular backups of the database to safeguard from data loss and ensure data loss recovery.
Apply patches and software upgrades to the database when possible.
•Question:
•2018 Nov, Question 2d
•Identify two (2) tasks that a database administrator carries out to ensure the security of the database. [2] (This question has a qualifier: "security of the database")
•Answer:
•DBA set ups user accounts and password to ensure only authorized users can gain access to the database
•DBA set ups access rights/permissions to ensure the levels of access are given to appropriate person using the database
•DBA install and update anti-hacking and anti-virus software to secure the database
•Question:
•2018 May, Question 2c
•Identify three (3) tasks that are carried out by a database administrator. [3]
•Answer:
•DBA authorize and manage user access to the database
•Manage and maintain database security by installing anti-hacking software, anti-virus software and setting up user access rights/permissions
•Plans and implement database backup strategies, database loss recoveries
•Apply patches and updates to the database software
•Question:
•2018 May, Question 2d
•Customers can choose credit card to pay for an online booking for a local theatre. However, some customers are concerned that their personal information could be shared with unauthorized parties.
•Explain one way that the DBA could do to ensure the anonymity of the customers are maintained. [3] (One (1) way only but 3 three (3) marks)
•Answer:
•When booking for a movie, a customer should be given a unique number/identifier [1] and the unique number will be used to access the booking details of that particular customer only. [1]
•DBA can set up a primary key, unique number for each customer [1] in the customer details table so when the customer access their details, they can only see their own using their given primary key or unique customer number. [1]
•Question:
•2016 Nov, Question 2bi and 2015 Nov 3c (exactly same question)
•Explain two responsibilities of a DBA. [4] (asking two only but 4 marks)
•Answer: (1 mark for responsibility and 1 mark for further explanation)
•DBA is responsible for database security. [1] This means that the DBA set ups user access rights/permission levels. They also set up the user accounts and password. [1]
•DBA is responsible for updating the database objects/file structure. [1] This means that if there’s a need to create/edit tables, fields, queries and reports, the DBA will be the one to do it. [1]
•Question:
•2016 May, Question 3a
•Suggest two measures that a DBA could do to prevent personnel from misusing the database systems. [2]
•Answers:
•DBA grants different access rights to the personnel [1]
•DBA change or remove access rights to the personnel who consistently break rules or misuse the database. [1]
•DBA can make the data read-only to some personnel so they can only view it and not do something with it. [1]
A.3.2 Explain how end-users (regular users/non-technical users) can interact with a database.
•End-users can interact with the database using the application interfaces (GUI or screen)
•The application might have a screen for managing data, filtering data, and printing the data in a form of reports
A.3.3 Describe different methods of database recovery.
•WHAT IS DATABASE RECOVERY? - the process of restoring data that has been lost and making sure that the database is in the most updated and consistent state.
•https://www.youtube.com/watch?v=ls3gGWg8W4E
•Back-up; Back-up copies of the whole database is done regularly to ensure the database is at the most updated version of the original.
•System log; in the event of a disk crash, this method will recover a past copy of the database then reconstructs the more current state by redoing the operations of a committed transactions up to the time of failure.
•Shadow Paging; When a page is modified, a shadow page is allocated in which changes are made and when it’s ready to become durable(permanent), all pages that refer to the original are updated.
•https://www.youtube.com/watch?v=IF3QeD6CuF0
•Deferred Update; Does not physically udpate the database on disk until a transaction reached its commit point, if the transaction failed before reaching its commit point then it will not update the database so UNDO is not required.
•https://www.youtube.com/watch?v=lcyzk0v947U
•* Prior knowledge needed: Database transaction states