Database Environment Flashcards
What are the main components of a DBMS environment?
- Hardware
- Software
- Data
- Procedures
- People
Each component plays a crucial role in the effective functioning of a DBMS.
What functions does a DBMS provide?
- Data storage, retrieval, and update
- User-accessible catalog
- Transaction support
- Concurrency control
- Recovery services
- Authorisation services
- Data communication support
- Integrity services
- Utility services
These functions ensure the reliability and security of database management.
What is the purpose of the external level in the ANSI-SPARC architecture?
It describes the part of the database relevant to each user, representing users’ views of the database.
This level allows users to interact with the database without needing to understand its internal workings.
What does the conceptual level of the ANSI-SPARC architecture represent?
It provides a community view of the database, describing what data is stored and the relationships among data.
This level facilitates mapping between external and internal levels.
What is the internal level in the ANSI-SPARC architecture?
It describes how the data is physically stored on the computer.
This level deals with the actual storage structures used by the database.
What are the advantages of using a DBMS?
- Control of data redundancy
- Data consistency
- More information from integrated data
- Sharing of data across departments
- Improved data integrity and security
- Enforcement of standards
- Increased productivity
These advantages contribute to a more efficient and reliable data management system.
What are some disadvantages of DBMS?
- Complexity
- Size
- Cost
- Additional hardware requirements
- Performance issues
- Greater impact of a failure
These disadvantages can affect the implementation and maintenance of DBMS.
What does a Data Administrator (DA) do?
Responsible for management of data resources, database planning, development of standards, and advising senior managers.
The DA ensures database development aligns with corporate objectives.
What is the role of a Database Administrator (DBA)?
Responsible for the physical realization of the database, including design, implementation, security, and maintenance.
The DBA requires technical knowledge of the DBMS.
Fill in the blank: The _______ level describes how data is stored in the ANSI-SPARC three-level architecture.
Internal
True or False: The conceptual level in the ANSI-SPARC architecture can have multiple external views.
True
What is the purpose of the system catalog in a database?
It serves as a description of the data that provides program-data independence.
This allows changes to the data structure without affecting application programs.
How many levels exist in each level in the three-level architecture?
There can only ever be 1 conceptual level and 1 internal level, but there can be many external levels.
What is a major objective of the three-level architecture?
Data independence.
What is logical data independence?
Changes to the conceptual schema should not require changes to external schema or application programs.
What does physical data independence refer to?
Immunity of conceptual schema to changes in the internal schema.
What is the role of Data Definition Language (DDL)?
Allows the DBA or user to describe and name entities, attributes, and relationships.
What operations does Data Manipulation Language (DML) support?
Insertion, retrieval, modification, or deletion of existing data.
What is a Fourth Generation Language (4GL)?
Includes query languages, forms generators, report generators, graphics generators, and application generators.
What are the components of a data model?
- Structural part
- Manipulative part
- Set of integrity rules
What is the purpose of a data model?
To represent data in an understandable way.
What are the categories of data models?
- Object-based
- Record-based
- Physical
What is conceptual modeling?
The process of constructing a model of information use that is independent of implementation details.
What is the result of conceptual modeling?
A conceptual data model.
What is the client-server architecture?
A model where the server holds the database and the DBMS, while the client manages the user interface.
What are the advantages of client-server architecture?
- Wider access to existing databases
- Increased performance
- Possible reduction in hardware costs
- Reduction in communication costs
- Increased consistency
Fill in the blank: The internal structure of a database should be unaffected by changes to _______.
Physical aspects of storage
True or False: Users should be aware of changes made to the conceptual schema.
False
What does DBMS stand for?
Database Managment System
What are the names of each level in the ANSI-SPARC Architecture?
- External
- Conceptual
- Internal
What does DA stand for?
Data Administrator
What does DBA stand for?
Database Administrator
What does DDL stand for?
Data Definition Language
What does DML stand for?
Data Manipulation Language
Name 3 types of data models
- Object based
- Record based
- Physical
What does an object based data model include?
- Entities
- Attributes
- Relationships
What does a record based data model include?
A number of fixed formats records
What does a physical data model refer to?
How data is stored in the computer representing information
