Question $1($Marks: $10)$

Discuss the reasons why databases have advantages over manual data processing systems.

Question $2($Marks: $5)$

A database is divided into layers or tiers to manage data effectively. Briefly explain the differences

between the two database architecture tier types.

Question $3($Marks: $10)$

PL$/$SQL provides a user with many features. Briefly explain the following features:

$1.$ Block Structure $(3)$;

$2.$ Procedural Language Capabilities $(3)$;

$3.$ Complete Portability $(2)$;

$4.$ Tight Integration $(2).$

Question $4($Marks: $10)$

Consider the following PL$/$SQL query:

Make or replace procedure Student$\_$Count

$($course$\_$name INPUT tblResults.Course$\%$TYPE,

stud$\_$count SEND tblResults.Results$\%$TYPE$)$

IS

BEGIN

select count$($r$.$results$)$

into stud$\_$count

from tblResults r

where r$.$Course $=$ course$\_$name;

END;

set serveroutput on;

declaring

stud$\_$count tblResults.Results$\%$OF$\_$TYPE;

begin

$16$; $17$; $18$; $192019$

$$ The Independent Institute of Education $($Pty$)$ Ltd $2019$

Page $3$ of $3$

Count$\_$Student$(\text{'}$DISD$3\text{'},$stud$\_$count$)$;

dbms$\_$output.put$\_$line$(\text{'}---------------------------\text{'})$;

dbms$\_$output.put$\_$line$(\text{'}$Number of students are: $\text{'}||$ student$\_$count$)$;

end;

The code above has seven errors. Identify at least five of the errors and rewrite the code so that it

would produce a valid output.

Question $5($Marks: $10)$

Oracle provides a database developer with the functionality to create procedures and functions.

Discuss any five differences between procedures and functions.

Question $6($Marks: $5)$

Explain the three advantages of implementing exceptions as a means of handling errors.