Prelim2 Flashcards
What is the first step in designing a database?
Data Modeling
Data Modeling refers to the process of creating a specific data model for a determined problem domain.
What is a data model?
A relatively simple representation, usually graphical, of more complex real-world data structures.
What are the basic building blocks of a data model?
- Entity
- Attribute
- Relationship
What is an entity in a data model?
It is a person, place, thing, or event about which data will be collected and stored.
What is an attribute in a data model?
It is a characteristic of an entity.
What does a relationship describe in a data model?
An association among entities.
What are the three types of relationships in a data model?
- One-to-one (1:1)
- One-to-many (1:M)
- Many-to-many (M:M)
What is the hierarchical model?
A data model developed in the 1960s to manage large amounts of data for complex manufacturing projects.
How is the hierarchical model represented?
By an upside-down tree containing levels or segments.
What is the purpose of the network model?
To represent complex data relationships more effectively than the hierarchical model.
What is a schema in the context of a database?
The conceptual organization of the entire database as viewed by the database administrator.
What does DML stand for?
Data Manipulation Language.
What is the relational model?
A data model introduced in 1970 by E. F. Codd, representing a major breakthrough for users and designers.
What is the entity relationship model (ERM)?
A graphical representation of entities and their relationships in a database structure.
What does the Object-Oriented Data Model (OODM) represent?
Both data and its relationships contained in a single structure known as an object.
What is inheritance in the context of object-oriented data models?
The ability of an object within the class hierarchy to inherit attributes.
What is the role of UML in object-oriented data models?
To depict object-oriented data models using class diagrams.
What does XML stand for?
Extensible Markup Language.
What are the three levels of data abstraction defined by ANSI/SPARC?
- External Model
- Conceptual Model
- Internal Model
What is the external model?
The end user’s view of the data environment.
What does the conceptual model represent?
A global view of the entire database by the organization.
What is the internal model?
The representation of the database as seen by the DBMS.
What is the physical model in data abstraction?
Describes the way data is saved on storage media.
What are the key characteristics of Big Data?
- Volume
- Velocity
- Variety
What is NoSQL?
A large-scale distributed database system that stores structured and unstructured data.
What is a key advantage of NoSQL databases?
They provide high scalability, high availability, and fault tolerance.
True or False: NoSQL databases are based on the relational model.
False
What does ‘velocity’ refer to in Big Data?
The speed with which data grows and the need to process it quickly.
Fill in the blank: The __________ model is a data model that represents complex relationships more effectively than the hierarchical model.
Network
What is the significance of the relational model introduced by E. F. Codd?
It represented a major breakthrough for both users and designers.
