Computing 2 Flashcards
What does a CPU contain?
The arithmetic and logic unit (ALU)
The control unit
What does the boot sequence contain?
It contains the boot loader
Multiple processor core Advantages and disadvantages of
Uses multiple CPUs working together. More data is processed simultaneously, but more complicated operating systems are needed to manage them
Main considerations when selecting storage
Capacity
Speed
Portability
Durability
Reliability
Types of software
System software
Application software
Utility software
Advantages and disadvantages of custom written software
It should have exactly the features required, and it should require special adaptation to be made after installation
It may not have been extensively rested, it may be expensive, and it may take a long time to develop
Disadvantages of off the shelf software
Probably won’t be exactly what the customer needs
May need extensive customisation
Customers might have to search for training providers
Open source software. Advantages and disadvantages
Advantages - it may be free of charge - - it can be altered because the source code is available Disadvantages: - there are no maintenance contracts - there is no one contact if there are problems - updates may not happen or come at irregular intervals
Proprietary software. Advantages and disadvantages.
Advantages: - there is someone to go to if there is a problem - it should have been extensively tested Disadvantages: - it can be expensive - it may be inflexible to users needs
How can data be lost?
A catastrophe, such as fire or flood
An accident, such as an employer deleting data
Malicious action
How can data be protected against loss?
Making regular backup
Having a mirror database server
Strong backup in a safe place
Restricting access
Database Management System
This software that looks after a database at a fundamental level:
To create database applications
Protect data
Run queries to extract data
Keep data consistent
Keep data accurate
Separation of data and applications
It is important to separate the applications from the data so that: -programmers do not have to worry that their applications might damage existing data structures -new applications can be written without restructuring the data -data can be more easily shared between applications
Three principal layouts p59
Bus
Star
Ring
