[Year 12 IPM] Redundancy

[Mark Kelly]

Data redundancy (DR) can be good and bad.

When bad, it wastes storage space or blows out the size of a data 
structure with no benefit (e.g. as previously mentioned, the same data 
stored in 2 tables in a database).  I suppose DR can even mean the same 
data stored in multiple copies of the same file.  Database normalization 
can help fix DR.

On the positive side, DR can be good.  Backups are classic examples of 
DR.  Backup servers or backup data hosts which take over in case the 
primary host fails) are DR.  RAID's mirroring is DR.

Dunno if that helps anyone  :-o

Andrew Sutton wrote:
> Doesn't it also have to do with two fields in the one table that are
> essentially giving you the same information? For example, In a table, You
> shouldn't need the Age field if you have an accurate D.O.B. field.  
> 
> -----Original Message-----
> From: ipm-bounces at edulists.com.au [mailto:ipm-bounces at edulists.com.au] On
> Behalf Of Geraldine McKenna
> Sent: Tuesday, 11 October 2005 11:41 PM
> To: Year 12 Information Technology Processing and Management
> Teachers'MailingList
> Subject: [Year 12 IPM] Redundancy
> 
> Hi everyone,
> Thanks for the help this list has provided throughout the year again!! Could
> someone plese explain to me the meaning of 'data redundancy'? My
> understanding is that it relates to loss of data and I also think it is
> different to 'data integrity' but am not clear about these. It has come up
> as a result of students having just completed the Insight Trial Exam paper.
> Thanks in advance.
> Geraldine McKenna
> IT Coordinator
> Avila College
> Mt Waverley
> 
> _______________________________________________
> http://www.edulists.com.au - FAQ, resources, subscribe, unsubscribe
> IPM Mailing List kindly supported by
> http://www.vcaa.vic.edu.au - Victorian Curriculum and Assessment Authority
> and
> http://www.vitta.org.au  - VITTA Victorian Information Technology Teachers
> Association Inc
> 
> 
> 
> 
> Important - 
> This email and any attachments may be confidential. If received in error, please contact us and delete all copies. Before opening or using attachments check them for viruses and defects. Regardless of any loss, damage or consequence, whether caused by the negligence of the sender or not, resulting directly or indirectly from the use of any attached files our liability is limited to resupplying any affected attachments. Any representations or opinions expressed are those of the individual sender, and not necessarily those of the Department of Education & Training.
> 
> _______________________________________________
> http://www.edulists.com.au - FAQ, resources, subscribe, unsubscribe
> IPM Mailing List kindly supported by
> http://www.vcaa.vic.edu.au - Victorian Curriculum and Assessment Authority and
> http://www.vitta.org.au  - VITTA Victorian Information Technology Teachers Association Inc
> 


-- 
Mark Kelly
Manager - Information Systems
McKinnon Secondary College
McKinnon Rd McKinnon 3204, Victoria Australia
Phone +613 95780844  Fax +613 95789253
http://www.mckinnonsc.vic.edu.au
IPM Lecture notes: http://vceit.com
Moderator: IPM Mailing List

Gosh you’re cute. Wanna buy a monkey?