26-05-2012, 10:28 AM
Components of a Modern Database Management System
Components of a Modern Database Management System.ppt (Size: 477.5 KB / Downloads: 29)
Most modern database management systems:
Are enterprise-wide
Are SQL-based
Use Internet technology
For communications
As a user front-end to the system
Fit the three-tiered model
Application-based File Systems
Old data storage and retrieval systems tended to be application based files systems.
Each application usually had its own data files
The file structure was developed independently for each application by the programmers.
The same data often appeared multiple times.
Files were often incompatible with each other.
The file structure was developed independently for each application by the programmers.
initial design must include file structures
unique methods were harder to maintain
one data set was often incompatible with others
Structured Query Language – SQL
SQL is a well-defined, standardized language that includes language for data definition and language for data manipulation.
It may be used independently to manage and access a database, or it may be imbedded in other software, such as computer programming languages.