Storing and Retrieving Flashcards
What is storing and retrieving?
The two step process by which data can be saved and reloaded
What is the role of storing and retrieving?
Allows other processes to take place
For a temporary halt in the system
Backup and recovery
The transfer of data and information
What is random and sequential access?
Random access is the ability to access stored data in any order.
Sequential access is when data is stored or retrieved in a linear sequence mainly used for backups
What are volatile or non-volatile storage devices?
Volatile storage devices require a continuos power supply to maintain data whereas non-volatile storage does not.
What are the non-computer tools of storing and retrieving?
Paper based storage systems
Microfiches
Libraries
What are the social and ethical issues involved in storing and retrieving?
The security of stored data
Unauthorised retrieval of data
Advances in storing and retrievals techniques
What is RAID? Explain its two main forms?
RAID is a form of virtualised technology mainly used in network storage. RAID 0 uses the process of striping to split data into blocks and store them equally across the drives. RAID 1 uses the process of mirroring to write the same blocks of data across the drives.
What is the main purpose of optical disks? How do they store information?
Optical disks mainly store music data or computer software whilst also being able to hold high quality video. Information is stored through lasers which ‘burn’ data onto the disks
What are the main characteristics of flash memory?
Flash memory is a non-volatile electrical erasable and reprogrammable storage device. Like ROM it remembers information when the power is turned of and like RAM it can be erased and rewritten a large number of times
What are the uses and characteristics of magnetic tapes?
Used for storage of visual and audio data, it uses sequential access to access stored data. The data is stored in the taped via a magnetic coating and is mainly used for back ups
What is pessimistic and optimistic locking?
Pessimistic locking is occurs after one user has accessed a file and does not let any other uses edit or access it providing a read only version. Optimistic locking is where multiple users are allowed to access the same files but if information is edited warnings will alert the user
What is symmetrical and asymmetrical encryption?
Symmetrical encryption is where data is encrypted within the secondary storage through the use of a computer. Asymmetrical encryption involves a public and private key where the receiver sends out a public key to the sender and the receiver has their own unique private key to decrypt data sent.
