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Date November 2017 Marks available 2 Reference code 17N.2.SL.TZ0.1
Level SL Paper 2 Time zone no time zone
Command term Define Question number 1 Adapted from N/A

Question

Define the term database transaction.

[2]
a.

Explain the importance of durability in a database transaction.

[2]
b.

Identify two different types of relationships within databases.

[2]
c.

Describe the nature of the data dictionary.

[4]
d.

Identify four responsibilities of a database administrator.

[4]
e.

Markscheme

Award marks as follow up to [2 max].
Award [1] for:
a unit of work/logical action;

performed on a database;
independent of other transactions; 
changes state of the database;

Example answer 1
A database transaction is a logical unit that is independently executed;
For data retrieval or updates;

Example answer 2
A database transaction is a unit of work;
That is either executed in full or not executed at all;

Example answer 3
A database transaction is a way of representing a state change;
And has four properties, known as ACID;

Example answer 4
A database transaction usually means a sequence of steps, treated as a unit;
For the purposes of satisfying a client’s request;

Example answer 5
A database transaction is a process carried out on a database;
Which may change its state, for example: moving money between bank accounts;

a.

Award up to [2 max].

Example answer 1
Durability is important because transaction data changes must be available;
Even in the event of database failure;

Example answer 2
Durability means that if the system says the transaction has been committed;
The client does not need to worry about it because transactions that have been committed will survive permanently;

Example answer 3
Durability in databases is an important property because it ensures transactions are saved permanently;
And do not accidentally disappear or get erased;

b.

Award up to [2 max]
One to one;
One to many;
Many to one;
Many to many;

c.

Award [1] for stating what a data dictionary is and up to [3 max] for describing its contents.

It is a set of tables/a database that provides information/meta-data about the database;

A data dictionary contains
The definitions of records/entities in the database;
How much space has been allocated for and is currently used;
Default values for columns/attributes;
Integrity constraint information;
Names of (database) users, their privileges and roles;
Auditing information such as who has accessed or updated data records;
etc. (any other general database information);

They do not contain any actual data from the database, it contains only information for managing it (without a data dictionary a DBMS cannot access data from the database);
Data dictionaries are usually hidden from users to prevent them from (accidentally) deleting/changing/destroying its contents;

d.

Award up to [4 max].
To direct and perform all activities related to a database system;
Installing and configuring software;
Creating new databases;
Designing the database schema and creating any necessary database objects;
Ensure database security is implemented to safeguard the data;
Back up and recover the database;
Work closely with application developers and system administrators to ensure all database needs are being met;
Apply patches or upgrades to the database as needed;
Training employees who use the database;

e.

Examiners report

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

Syllabus sections

Option A: Databases » A.1 Basic concepts
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Option A: Databases

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