DP Computer Science Questionbank

Identify two types of update anomaly.

Identify three ways that incorrect data could be prevented from being added into the School_phone_no field.

Outline why data validation is difficult for the Book_Title attribute.

Outline why atomicity is important within a database.

Outline how data consistency can be maintained in transactions in this database system.

Explain how concurrent use of the school database is possible in this situation.

Define the term database transaction.

Explain the importance of durability in a database transaction.

With reference to the relation CLASS_TABLE distinguish between data and information.

Explain the role of data validation and data verification.

Explain how Total could be validated.

Outline the difference between an information system and a database.

A bank maintains a database that stores details of clients and their accounts.

A client wants to transfer money between two accounts held at the same bank.

Explain how the ACID (Atomicity, Consistency, Isolation, Durability) properties would apply in the context of this database transaction.

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.

Outline, using an example, how data validation can ensure that data is entered into the birds database correctly.

Outline, using an example, how data verification can ensure that data is entered into the birds database correctly.

Distinguish between data and information when entering the length of a spoonbill’s beak in the database.

Explain why Date of birth has been separated into three fields.

Define the term database transaction.

Outline how the Billetmania information system would utilize a database.

Explain the importance of transaction durability to Billetmania when clients book tickets.

Construct the entity relationship diagram (ERD) that shows the relationship between the bank branch, the customers and their loans.

With reference to the table LOANS, state the output of the following query:

SELECT LOANS.Loan_ID, LOANS.Customer_ID, LOANS.Amount, LOANS.Type
FROM LOANS
WHERE (LOANS.Amount > 600000) AND ((LOANS.Type = "Home") OR
(LOANS.Type = "Venture"));

Identify the steps to create a query to find the names of customers whose account balance is greater than $300 000.

Explain how controlling access rights contributes to the security of the Galaxy Bank database.

Explain how row locking ensures the consistency of the data in the Galaxy Bank database.

Explain one benefit of normalizing a database.

Outline what would be necessary to make the above unnormalized table conform to 1st Normal Form (1NF).

Construct the 3rd Normal Form (3NF) of the unnormalized relation shown above.

Explain the difference between 2nd Normal Form (2NF) and 3rd Normal Form (3NF).

Construct the entity-relationship diagram (ERD) for this scenario.

State the result from the following query:

SELECT Book_Title
FROM BOOK
WHERE Genre = "Non-fiction"
AND ISBN = '0-98124-612-2'

Construct a query to find the titles of the books published by “Orlando Crux”.

Some data in the MRBS database is redundant.

Outline one problem caused by redundant data.

Describe two ways that data security in the school's database can be maintained.

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.

Identify two different types of relationships within databases.

Describe the nature of the data dictionary.

Describe the steps in a query that will output the names of all students who earned the maximum mark on Exam_Two.

Describe the steps in a query that will output the Student_IDs of all candidates who passed.

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 an appropriate data type for Prod_Price.

Construct the steps in a query to output the names of all products supplied by Veggy Co. with prices in the range from 4.00 to 10.00 inclusive.

Outline the redundant data in this relation.

Explain the problems that may arise for the following function performed on the given relation. In your answer, you should give an appropriate example: Inserting a new tuple with an item that is supplied by existing supplier.

Explain the problems that may arise for the following function performed on the given relation. In your answer, you should give an appropriate example: Deleting a tuple from the relation.

Explain the problems that may arise for the following function performed on the given relation. In your answer, you should give an appropriate example: Modifying a specific attribute value in the tuple.

Construct the database in the 3rd normal form (3NF) using the notation

Greengrocer (Prod_ID, Prod_Name, Prod_Price, Supp_Name, Supp_Contact, Supp_Phone)You must show all your workings.

You must show all your workings.

Identify one reason why the teacher’s name has been split into two fields.

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.

Construct an entity-relationship-diagram that shows the relationships between the class, order and family.

Identify two characteristics of a conceptual schema.

Explain why the use of data modelling is critical to the success of a database, such as the one used in this scenario.

Explain, using the example described in the scenario, why referential integrity is important in databases.

Identify two characteristics that make a database unnormalized.

Outline why data redundancy may be a problem in the LORRY table.

Identify the steps to create a query to find the names and telephone numbers of the drivers who drive lorries that have more than 60 cubic metres of trailer space.

Normalize the database to 3NF. Use the same format as shown, ensuring that primary keys are clearly indicated by underlining them.

Construct the entity-relationship diagram (ERD) that shows the relationship between the individual, their driving license, and their vehicle(s).

Outline two issues caused by storing redundant data.

Explain how the Billetmania database management system ensures that a seat is not booked by two people simultaneously.

Define the term record.

Identify the steps to create a query to find the vineyards and names of fruity wines where the quantity in stock is between 25 and 35 bottles.

Identify the steps to create a non-persistent derived field called TotalPrice, which would hold the total value of wine stored for each record.

Outline why the inclusion of a derived field will not affect the normalization of a database.

Construct the 3rd Normal Form (3NF) of the unnormalized Wine file.

Outline why a single-field primary key is not always an appropriate solution for normalized databases.

Outline two methods of database recovery that can be used to restore the system.

Identify three tasks that are carried out by the database administrator (DBA).

Customers can choose a credit card as their method of payment. However, some customers are concerned that their personal information could get shared with unauthorized third parties.

Explain one way that the DBA at ShowTime can ensure the anonymity of the customers is 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.

Identify four responsibilities of a database administrator.

A bank holds large volumes of financial and personal information about its clients in its database.

Discuss whether this database should be open to interrogation by the police or the Government.

Identify two tasks that a database administrator carries out to ensure the security of the database.

Outline one reason why there may be concerns about the amount of personal information that is requested.

Identify two tasks that are carried out by the database administrator (DBA).

Explain two reasons why medical information should not be stored in the Person table.

Outline two situations where data stored by the Driving Licensing Agency may need to be open to interrogation by other parties.

Outline how the Billetmania information system would utilize a database.

Describe how deviation detection can be used to analyse this data.

Outline why data warehouses tend to use unnormalized data sets.

Identify three precautions to be taken before extraction is carried out on the database.

Outline why data warehousing is time dependent.

Explain why Basking Coats could use association analysis to improve the marketing of its products.

Basking Coats has decided to use an object-oriented database rather than a relational database to store its data.

Explain why Basking Coats would use an object-oriented database rather than a relational database to store its data.

Explain how cluster analysis can be used to achieve the aims of the system that is described above.

Outline why data warehousing is time dependent.

Outline one reason why ZCC uses a data warehouse.

Outline why transformation of the data is necessary prior to it being loaded into the data warehouse.

Compare cluster analysis and classification as techniques for discovering patterns in ZCC's data.

Describe how the process of deviation detection can be applied to identify customers who are likely to miss the payment deadline for their purchases from ZCC.

ZCC is aware that other data mining and detection techniques will allow more informed marketing decisions to be made.

Explain how database segmentation and link analysis can be used by ZCC to improve their marketing strategies.

Evaluate the use of an object-oriented database as opposed to a relational database.

Define a spatial database.

Explain one benefit of database segmentation to the telecommunication company.

Explain how ETL processes could be used in data preparation.

Distinguish between the use of association and sequential patterns as data mining techniques.

Describe how deviation detection could be used to detect fraud at the telecommunications company.

Customers who decide to leave the telecommunication company for a competitor may result in huge losses for the telecommunications company.

Explain with the use of an example, how predictive modelling could be used to optimize information sent to existing customers.

Identify four sources of information that could be incorporated in the data warehouse.

Outline two differences between a data warehouse and database.

Explain how the Extract, Transform, Load (ETL) processes can be used to address the problems related to data migration.

Outline one ethical problem that may result from data mining.

Explain how cluster analysis can be used to improve the advertising strategy of the tourism companies.

Explain the importance of link analysis in exploring patterns in data mining.

Explain two advantages of using a relational database rather than an object-oriented database.

State two characteristics of a data warehouse.

Outline why data needs to be transformed before it can be loaded into the data warehouse.

Outline why opinion poll data and other election data are timestamped when added to the data warehouse.

Outline why analytics companies use link analysis.

Outline why analytics companies use deviation detection.

Once data has been loaded into a data warehouse it can be mined. The use of data analytics is believed to have been important to the outcome of the US election campaign.

Discuss whether the advantages of data mining techniques in this scenario outweigh the disadvantages.