Information Systems for you

Questions (Page 65)
	A	Several pupils could have the same surname and it is necessary to distinguish between them.
	B	You need the system to store details about previous pupils as well as have room to store details about pupils in the future.
	C	Date of birth could be used. It is less likely that two pupils will have the same name and date of birth.

Questions (Page 68)
	A	A spare copy taken for security purposes in case the original copy becomes damaged or stolen.
	B	The backups are usually on the hard drive. If the computer were stolen then the original copy and the backup copy could be lost.
	C	He should not keep the original copies with the backup copies. If the box were to be stolen then all the data will be lost.

Test Yourself (Page 70)
	A	database
	B	files
	C	records
	D	fields
	E	structure
	F	duplication
	G	master
	H	transaction
	I	security
	J	grandfather, son

Things To Do (page 71)
1(a)		A
(b)		D
(c)		I
(d)		A
(e)		A
(f)		D
(g)		I
(h)		D
(i)		A
(j)		D

2(a)		5
(b)		5
(c)	(i)	Admission number
	(ii)	In case there are pupils with the same name.
(d)		Address so that letters can be sent home. Contact numbers so that parents can be phoned up in case of an emergency.

Examination Questions (page 335)

1(a)

(b)

(c)

Accession Number

(d)

To uniquely define a row in the file/table.

(e)

Title	Date of Publication
Computer Studies	1994
Business GNVQ	1993
Computing	1992
Compilers	1991
Computer Graphics	1990
C Programming	1989

(f)

(i)

(ii)

Book was never returned/Book destroyed/Book removed from library because out of date etc.
A new book was added to the library.

A tape streamer is used as a high capacity storage device used to backup a hard drive. It consists of a magnetic tape in a plastic cartridge unit.

3(a)

(i)

(ii)

Verification - a check to make sure that what was typed in is exactly the same as that on the source document.
Validation is a check performed by the applications software to make sure that the data being entered is reasonable/allowable.

(b)

(i)

(ii)
(iii)

You can work out how much space is needed. Easier to program.
A smaller amount of memory is used.
Text, Date, Memo, Autonumber/counter, text, currency, logical, OLE etc

(c)

It is quicker to type in.
Fewer errors because data is consistent.

Method	Tape	Disk
Serial	Yes	Yes
Sequential	Yes	Yes
Indexed sequential	No	Yes
Direct (Random)	No	Yes

5(a)

(b)

It is a unique field for a particular record/row in the table.

(c)

It only allows data to be entered into the field that is consistent with the field type. You cannot enter alphabetic characters into a numeric field.

6(a)

A structured and organised collection of files which can be used to extract the information in a variety of different ways.

(b)

Any two from the following: No duplication of data; Data can be held centrally and security can be supervised; A standard interface can be used for all the users.

(c)

Allows the user to specify the structure of the database. Provides a standard user interface.
Makes reporting easy
Provides security for the data held.