Week_1 Flashcards
What is a database?
A database is a shared collection of logically related data, and a description of this data, designed to meet the information needs of an organization.
What is a database management system (DBMS)?
The software that manages and controls access to the database.
What is a database application?
A program that interacts with the database at some point of its execution.
Explain Program-Data Dependence
All file-based programs maintain metadata for each file they use. A change in a file’s data characteristics requires the modification of the data access programs.
Disadvantages of File-Based Systems
- Redundancy / duplication of the data
- Inconsistency arising from the redundancy
- Hard to share the data among multiple applications
- Data integrity hard to maintain
- Incompatible file formats
2 Limitations on File-Based Systems
- The definition of the data is embedded in application programs, rather than being stored separately and independently.
- There is no control over the access and the manipulation of the data, beyond that imposed by the application programs.
What is an Entity?
A distinct object (person, place, thing, concept or event) to be represented in the database.
A Relationship is _______?
An association among entities.
What is an attribute?
An attribute describes some aspect of the object one wishes to record.
DBMS is ______?
A software that enables users to define, create, maintain and control access to the database.
What is an Application Program?
A computer program that interacts with the database by issuing an appropriate request (typically and SQL statement) to the DBMS.
