There are five major advantages of DBMS or database management systems: data structure, authorization control, processing speed, modular development, and independent back-up functionality. A DBMS is a computer software that manages the organization and access to data in a database.
A DBMS allows large amounts of data to be stored in the most efficient manner possible. The data is stored in lists of independent information. Additional data sets can be added at any time. Relationships between the data sets are defined in the DBMS, and can be altered without affecting the data.
For example, a simple database has three tables: car names, engine sizes, and seating capacity. Reports or queries can be created to access these tables and link them together in a logical way. Six months later, another table can be added listing the safety ratings. These tables can be updated independently, with no impact on any reports already created. The database management system can be programmed to run different queries or reports to retrieve specific data.
It is very common to have different access levels built into a database system, and a DBMS makes this very easy to manage. Access can be defined at the data table level. If the user does not have access to a specific table, they cannot run any query that uses data from that table. Control at this level is easy to maintain, and preferable to setting the access at the individual reporting level.
The processing speed and responsiveness of a computer system is much better with a DBMS than with a linear computer program. Common functions, such as count, sum, and calculate are programmed at the DBMS level. In a DBMS, the programs to update, report, and store the information are set at the system level.
Each section of the system can reuse code from another section or module. For example, inventory data can be stored and maintained in a module that is completely separate from sales data. However, queries can be written to combine information from these two modules without needing to change the database structure. This assumes that both modules are in the same database management system.
DBMS provide a separate architecture for the data and the programming logic. This separation allows the database manager to back up just the data to one hard drive and the programming onto another. Should the hardware fail for either system, it is possible to redirect the program server to utilize the data from the back-up, and vice versa.