Firstly, if i may ask; What is database? A database is a highly organized collection of data
accessible to the entire application program within system. computer softwares positively impacts Within a
database, duplication of data is carefully controlled and each program is afforded
a selective view of the data which is appropriate to that application.
accessible to the entire application program within system. computer softwares positively impacts Within a
database, duplication of data is carefully controlled and each program is afforded
a selective view of the data which is appropriate to that application.
A database allows the storage of different types of records with appropriate
interconnections. Since data is not usually duplicated in a
database, the problem of inconsistency which results form inability to
update duplicate copies of the same data is effectively solved.
Advantages of databases
- No duplication of data
- No redundancy of data
- Consistency of data is enhanced
- It saves time
- It enhances file sharing or sharing of data
- Access to file is in full control
- Disadvantages of databases
- It is very costly to maintain
- It requires sophisticated hardware and software
- It requires a specialist to control
- A single error can lead to chain of erroneous results from usages
METHODS OF OPERATING AND MODES OF ACCESS:
Multiprogramming: This is a
technique where by two or more jobs is proceed at the same time. We
may also define multiprogramming as a technique where by two or more programs
are residing in the main memory of a computer at the same time.
technique where by two or more jobs is proceed at the same time. We
may also define multiprogramming as a technique where by two or more programs
are residing in the main memory of a computer at the same time.
Multiprocessing: This is a
situation where by two or more jobs are being processed simultaneously by tow
ore more inter-connected control or processing units.
situation where by two or more jobs are being processed simultaneously by tow
ore more inter-connected control or processing units.
Batch Processing: This is a
situation whereby input and output devices are directly connected to the CPU
and they are under the control of CPU.
situation whereby input and output devices are directly connected to the CPU
and they are under the control of CPU.
On-Line Processing: This is a
situation whereby input and output devices are directly connected to the CPU
and they are under the control of CPU.
situation whereby input and output devices are directly connected to the CPU
and they are under the control of CPU.
Interactive Computing: This is
a situation where there are two way communications between the operator and the
computer
a situation where there are two way communications between the operator and the
computer
Multi Access: This occurs if
the computer allows interactive facilities to more than one user at a time.
the computer allows interactive facilities to more than one user at a time.
Real time System:
This is a system whereby computer response to the users request is terribly
fast
This is a system whereby computer response to the users request is terribly
fast
Time Sharing: This is the
process whereby computer time is divided among many users in order to give room
for much access.
process whereby computer time is divided among many users in order to give room
for much access.
Teleprocessing: this is a method of data processing whereby
input and output devices are in different location from the CPU) i.e. Local
Area Network.
INTERRUPT
An interrupt is a break in the normal sequence of execution of a program or a
switch of control from one program to another. The following are the causes of
interrupt.
Power failure
Arithmetic or logic error
Hardware malfunction
External interrupt
