A school maintains a database of students’ details and teaching resources on a central server. This data can be accessed by all teachers in the school.
Teachers may need to edit resources when preparing their lessons.
When storing student details, data security is an important consideration.
The school has appointed a database administrator (DBA).
A DBA is required to carry out tasks such as ensuring there is a strategy to recover the database if it becomes corrupted and that the data is shared ethically.
Explain how concurrent use of the school database is possible in this situation.
Describe two ways that data security in the school's database can be maintained.
Describe one strategy that could be used to ensure the data can be recovered if the database becomes corrupted.
Suggest how the privacy of student data can be ensured.
Consider the following example relation. It holds data about a number of teachers and students from different schools who volunteer to support the local community on particular days.
SCHOOL_VOLUNTEERS_TABLE (School_Name, Code, Address, Date, Num_Volunteers)
The key attributes are underlined.
State what is meant by redundant data in databases.
Explain one issue that can be caused by redundant data in a database.
Identify three characteristics of the 1st Normal Form (1NF) which are evident in this relation.
Explain why a compound key is used for the SCHOOL_VOLUNTEERS_TABLE relation.
The following shows the normalized SCHOOL_VOLUNTEERS_TABLE relation:
SCHOOLS_TABLE
Code, School_Name, Address
VOLUNTEERS_TABLE
Code, Date, Num_Volunteers
Discuss whether these relations are in third normal form (3NF).
Define the term database management system (DBMS).
Identify three characteristics of logical schema.
Outline the purpose of a data definition language (DDL).
Identify two tasks that a database administrator carries out to ensure the security of the database.
Define the term database transaction.
Explain the importance of durability in a database transaction.
Identify two different types of relationships within databases.
Describe the nature of the data dictionary.
Identify four responsibilities of a database administrator.
Pablo has claimed that the use of blockchain technology for the MONS cryptocurrency will mean the cryptocurrency is both secure and scalable. To what extent do you agree with Pablo?
Armour Hardware Company has the following data about salespersons and the quantities of items sold.
Each salesperson can sell many different products.
SALES_PERSON
Outline two reasons why databases are normalized.
Outline why the SALES_PERSON table is not in 1st Normal Form (1NF).
Construct the 3rd Normal Form (3NF) of the unnormalized relation shown above.
Outline why it is necessary to ensure that referential integrity is maintained in databases.
Outline why a primary key may consist of more than one attribute.
One-to-7 is an international organization that works with teachers and other educators. One department within this organization provides an online forum for teachers to discuss ideas for lessons and to share resources.
In order to access this forum teachers are required to submit the following information, which will be stored in a table in the database.
Figure 1: Online form to register personal details to the One-to-7 forum
Once the submit button on the online form has been selected, the personal data is input into the database.
Once the teacher is registered they can post comments on the forum.
The One-to-7 database in managed by the database administrator (DBA).
Identify one reason why the teacher’s name has been split into two fields.
Outline one reason why there may be concerns about the amount of personal information that is requested.
Outline why the transaction needs to be atomic in the context of this scenario.
Explain how transactions are managed to ensure isolation when registered teachers add comments to a discussion thread on the forum.
Identify two tasks that are carried out by the database administrator (DBA).
The DBA is considering using the email address as the primary key, but is concerned that many of the 250 000 educators who are registering for this online forum may have more than one email address. Users may create duplicate accounts, deliberately or accidently, by using different email addresses as usernames.
Explain the factors that would need to be considered in using a composite primary key instead of only using the email address.
A company lets tourists hire bikes. The data about bikes and hirers is stored in a database file. The following table shows this data for one day. BikeHireTable | HirerID | HName | HPhone | TimeOut | TimeIn | BikeID | BikeMake | BikeModel | | :--- | :--- | :--- | :---: | :---: | :---: | :---: | :---: | | BL567 | Boris Lok | 99123456 | 09:00 | 11:00 | DU12 | BMS_11 | A | | CL167 | Ivy Lok | 93123455 | 09:00 | 11:00 | DU14 | AVG_00 | B | | AL751 | Ann Summer | 43453657 | 09:00 | 17:00 | DU54 | AVG_00 | A | | FC345 | Fred Cohen | 38321432 | 10:00 | 15:00 | DU23 | XYZ_94 | C | | ... | ... | ... | ... | ... | ... | ... | ... | The structure of the table can be summarized using the following shorthand notation. BikeHireTable (HirerID, HName, HPhone, TimeOut, TimeIn, BikeID, BikeMake, BikeModel)
Identify three functions of a database management system in an application such as hiring bikes.
Outline the purpose of normalization.
State the characteristics of 1st Normal form (1NF);
State the characteristics of 2nd Normal form (2NF);
State the characteristics of 3rd Normal form (3NF).
Construct the database to 3NF. Using the shorthand notation, clearly show the structure of the database in the 1st, 2nd and 3rd normal forms.
Outline what is meant by a database management system.
Outline one advantage of using beta testing prior to the release of a new product.
Describe how a Merkle tree stores the hash addresses for the blockchain technology.
Explain why the residents of Santa Monica may be concerned by the lack of a central authority to manage MONS transactions.