2. DBMS
A database management system (dbms) is a
collection of programs that manages the database
structure and controls access to the data stored in
the database".
The dbms serves as the intermediary between the
user and the database. The database structure itself is
stored as a collection of files, so, we can access the
data in those files through the dbms.
4. REDUCED DA
TA REDUNDANCY
Definition - what does data redundancy mean?
Data redundancy is a condition created within a database or data storage
technology in which the same piece of data is held in two separate places.
This can mean two different fields within a single database, or two different spots in
multiple software environments or platforms. Whenever data is repeated, this
basically constitutes data redundancy. This can occur by accident, but is also done
deliberately for backup and recovery purposes.
Dbms allows users to access centrally managed database that reduces
redundancy and saves storage space
5. ELIMINATION OF
INCONSISTENCIES
Data inconsistency is a condition that occurs between files when
similar data is kept in different formats in two different files, or
when matching of data must be done between files. As a result of
the data inconsistency, these files duplicate some data such as
addresses and names, compromising data integrity.
By a system called propagating updates changes made at one place
are automatically made at all similar locations
6. DA
T
A SECURITY
The more users access the data, the greater the risks of data security breaches.
Corporations invest considerable amounts of time, effort, and money to ensure
that corporate data are used properly. A dbms provides a framework for better
enforcement of data privacy and security policies.
Level 1 – whether user has authority to use system
Level 2 – whether demanded file is accessible
Level 3 – analyse permission to add, modify, or delete the file
7. EASIER DATAACCESS TO USERS
The dbms makes it possible to produce quick answers to ad hoc queries. From
a database perspective, a query is a specific request issued to the dbms for
data manipulation—for example, to read or update the data. Simply put, a
query is a question, and an ad hoc query is a spur-of-the-moment question.
The dbms sends back an answer (called the query result set) to the
application. For example, end users, when dealing with large amounts of sales
data, might want quick answers to questions (ad hoc queries) such as:
- What was the volume of sales by product during the past six months?
-What is the sales bonus figure for each of our salespeople during the
past three months?
- How many of our customers have credit balances of 3,000 or more?
8. IMPROVED DECISION MAKING
Better-managed data and improved data access make it
possible to generate better-quality information, on which
better decisions are based. The quality of the information
generated depends on the quality of the underlying data.
Data quality is a comprehensive approach to promoting the
accuracy, validity, and timeliness of the data. While the
dbms does not guarantee data quality, it provides a
framework to facilitate data quality initiatives.
9. BACKUP AND RECOVERY
A dbms must provide facilities for recovering from hardware or
software failures. The backup and recovery subsystem of the dbms is
responsible for recovery. For example, if the computer system fails in
the middle of a complex update program, the recovery subsystem is
responsible for making sure that the database is restored to the state it
was in before the program started executing.
Other reasons may be:-
1. Disk crash
2. Software errors
