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Date November 2018 Marks available 6 Reference code 18N.2.SL.TZ0.1
Level SL Paper 2 Time zone no time zone
Command term Discuss Question number 1 Adapted from N/A

Question

Outline the difference between an information system and a database.

[3]
a.

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.

[8]
b.

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.

[6]
c.

Markscheme

Award up to [3 max].
Award [1] for a definition of an information system, [1] for a definition of a database and [1] for the relationship between the two.
An information system is the collection of software, hardware, networking infrastructure, human resources and databases that provide the storage, processing and communication/distribution of information;
A database is an organized collection of data (organized so that its contents can easily be accessed, processed, and updated);
A database is a subset of the information system;

a.

Award up to [8 max].
Award up to [2 max] for each of the four properties,
Award [1] for an explanation of the property and [1] in relation to the money transfer transaction.

Example answers:

Atomicity:
Ensures that either all changes to data are performed as if they are a single operation or none of them are performed;
In moving money from one account to another, it ensures that if a debit is made successfully from one account then the corresponding credit is made to the other account;

Consistency:
Ensures that data is in a consistent state when a transaction begins and when it ends / ensures that only valid data is written in the database;
In transferring money from one account to another, it ensures that the total value of money in both the accounts is the same at the beginning and at the end of each transaction;

Isolation:
Ensures that intermediate state of a transaction is invisible to other transactions;
In moving money from one account to another the isolation property ensures that another transaction might see one account or the other but cannot see both accounts;

Durability:
Ensures that after a transaction successfully completes, changes to data persist and are not undone even in the event of a system failure;
In moving money from one account to another durability property ensures that the changes made to each account are permanent;

b.

Award up to [6 max].
Award [1] for identifying an advantage of these databases being open to interrogation and an additional [1] for each development of that advantage up to [3 max].
Award [1] for identifying a disadvantage of these databases being open to interrogation and an additional [1] for each development of that disadvantage up to [3 max].
Award [1] for a valid conclusion.
If there is no conclusion, award [5 max].

Advantages:
Sharing the information may enable it to be made accessible to organizations such as the Police or the Government that may not have access to it;
This means that it could be used to detect fraudulent financial activities;
Leading to reduced insurance or health insurance premiums as monies are not lost from the system that create artificially high premiums;

Disadvantages:
Misuse of information / security issues;
Information from this database may enable the account details of the clients to be shared with third parties;
Who may use this information to take money from their accounts;

Conclusion:
Although the information may be shared, the overall benefits from a reduction in fraudulent crime or inflated insurance premiums is greater than the potential for this information to get into the wrong hands;

c.

Examiners report

[N/A]
a.
[N/A]
b.
[N/A]
c.

Syllabus sections

Option A: Databases » A.3 Further aspects of database management
Option A: Databases

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