Database Systems Overview from Database Lecture 1 & 2.

Flashcards based on key concepts from Database Lecture 1 & 2.

Data

Raw facts that are unprocessed.

Information

Processed data that is meaningful and useful.

DBMS

Database Management System; software that manages databases and enables users to store, modify, and extract information.

Schema

The structure of a database described in a formal language.

System Catalog

Stores metadata about the database, including structure, constraints, and authorized users.

Database Views

Used to provide different users with different perspectives of the database.

DDL

Data Definition Language; defines data structures.

DML

Data Manipulation Language; manipulates data.

Cloud Computing

On-demand network access to a shared pool of configurable computing resources.

DBaaS

Database as a Service; provides database functionality without typical DBMS interfaces.

What is the difference between data and information?

Data are raw facts; information is processed data that is meaningful and useful.

List three common uses of database systems in everyday life.

Banking, library systems, online shopping.

What is a major disadvantage of file-based systems?

Data redundancy and lack of integration between different systems.

What is a DBMS?

A Database Management System is software that manages databases and enables users to store, modify, and extract information from a database.

Mention two popular DBMS examples.

PostgreSQL, MySQL.

What are the advantages of using a DBMS?

Improved data sharing, data security, backup and recovery, integrity, and data consistency.

Define the term 'schema' in a database context.

A schema is the structure of a database described in a formal language.

What does the system catalog store?

Metadata about the database, such as structure, constraints, and authorized users.

What are database views used for?

To provide different users with different perspectives of the database.

List the five main components in a DBMS environment.

Hardware, software, data, procedures, people.

What are the three levels of the ANSI-SPARC database architecture?

External, Conceptual, Internal.

Explain logical data independence.

The capacity to change the conceptual schema without having to change external schemas or application programs.

What is physical data independence?

The capacity to change the internal schema without having to change the conceptual schema.

Differentiate between DDL and DML.

DDL defines data structures; DML manipulates data.

Name one procedural and one non-procedural DML.

Procedural: SQL with procedural extensions; Non-procedural: standard SQL SELECT.

What is a data model?

An abstract model that organizes elements of data and standardizes how they relate to one another.

List the three main categories of data models.

Object-based, Record-based, Physical.

What is conceptual modeling?

Creating a complete and accurate model of an organization's data independent of physical implementation.

What is a client-server architecture?

A model where clients run the UI and business logic, and servers host the database and DBMS.

Compare two-tier and three-tier architecture.

Two-tier: client and server; Three-tier: includes middle tier for application logic.

What is middleware?

Software that connects different applications or components in a distributed system.

What is a distributed database system?

A logically interrelated collection of shared data physically distributed over a network.

Define cloud computing.

On-demand network access to a shared pool of configurable computing resources.

What are the three service models in cloud computing?

SaaS, PaaS, IaaS.

What is DBaaS?

"Database as a Service

Mention one benefit and one risk of cloud computing.

Benefit: Scalability; Risk: Network dependency.