Database Design: Chapter 1 Flashcards
Databases evolved from what?
Computer file systems
Data are
Raw facts
Information is the result of
Processing raw data to reveal the meaning
What is Data processing
Organizing data to reveal patterns or as complex as making forecasts or drawing influences using statistical modelling.
What are Databases and what do they store?
Shared, integrated computer structure that store a collection of : End user data (interest to end users) and Metadata(data about data)
What is DBMS
A database Management system is a collection of programs. That manages the structure and controls access to data.
How many advantages of DBMS are there?
There are 7.
1. Improved data sharing
2. Improved data security
3. Better data integration
4. Minimized data inconsistency
5. improved data access
6. Improved decision making
7. Increased end-user productivity
A database can be classified according to :
- Number of users
- Database locations
- Expected type and extent of use
What is a single-user database and provide an example?
Database that supports only one user at a time. Ex: Desktop database
What is a Multiuser database and provide an example.
Database that supports multiple users at the same time. Ex; Workgroup and enterprise databases
What is a Centralized database and provide an example
Data located at a single site
What is a Distributed database and provide an example
Data distributed across several different sites. ex; Social Media
What is an operational database and provide an example
supports a company day to day operations. Insert data and quick. Ex: Transactional or production databases like grocery stores
What is a data warehouse and provide an example
Stores data used for tactical or strategic decisions.(take). Ask more complex questions.
What is unstructured data and provide an example?
Data that exist in their original state. (Voicemail)
What is structured data and provide an example.
Data resulted from formatting. Structured applied based on the type of processing to be performed. Ex; student record
What is semistructured data and provide an example?
Data that have been processed to some extent
What is Extensible markup language (XML).
Represent data elements in textual format. XML database support semistructured XML data. (exchange data)
Well designed database does
- Facilitates data management
- Generates accurate and valuable information
What are Data processing (DP) specialist
Convert computerfile strucutre from manual system.
-Wrote software that managed the data
- Designed the application programs
What is a manual system
- Served as a data repository fro small data
- Cumbersome for large collections
Structural dependence:
Access to a file is dependent on its own structure
– All file system programs must be modified to
conform to a new file structure
Structural independence:
Change file structure without affecting data access
Data dependence:
Data access changes when data storage characteristics change
Data independence:
Data storage characteristics do not affect data access
What is data redundancy
Same data stored unnecessarily in different places
What is data inconsistency
different and conflicting versions of same data occur at different places
What are data anomalies
abnormalities when all changes in redundant data are not made correctly.
- Update anomalies
- Insertion “””
- Deletion “”””
What are the five major parts of a database system
- Hardware
- People
- Software
- Procedures
- Data
What is the type of software required for a database system
Operating system software
DBMS software
Application programs and utility software
What are the steps for a data dictionary management?
DBMS stores definitions of data elements and
relationships (metadata) in a data dictionary
– DBMS looks up the required data component
structures and relationships
– Changes automatically recorded in the
dictionary
– DBMS provides data abstraction and removes
structural and data dependency
