DBMS Lecture Notes

Flashcards for reviewing DBMS lecture notes.

Data

Raw, unprocessed facts and figures with or without any meaning; can be numbers, text, images, or any other form of input that hasn’t been interpreted or analyzed.

Information

Data that has been processed, organized, or structured in a way that adds meaning or context, aiding in decision-making or understanding a situation.

Flat File System

A simple database system where data is stored in a single table or file without any structured relationships between records.

Database

A structured collection of data that is stored and managed to enable easy access, retrieval, and manipulation.

DBMS (Database Management System)

Software that provides an interface for users and applications to interact with databases, managing data, database engine, and schema.

Field

A single piece of data (also known as a column or attribute); a specific piece of information within a record in a database table.

Record

A complete set of related data items (also known as a row or tuple) typically associated with a single entity, stored in a table.

Object

An entity that can store data and interact with the database system, including tables, views, indexes, procedures, functions, and triggers.

Primary Key

A unique identifier for a record in a database table, ensuring each record can be uniquely identified.

Alternate Key

A column or set of columns in a database table that could have been chosen as the primary key but was not, serving as an additional unique identifier.

Super Key

Any combination of columns (attributes) in a database table that can uniquely identify each row in that table.

Candidate Key

A minimal super key, meaning it has no unnecessary attributes; the smallest possible combination of columns that can uniquely identify each row.

Composite Key

A type of candidate key that consists of two or more columns (attributes) that together uniquely identify a row in a table.

Foreign Key

An attribute (or a set of attributes) in one table that references the primary key of another table, used to establish and enforce a link between the data in the two tables.

E-R Model (Entity-Relationship Model)

A high-level conceptual data model used for designing databases, representing relationships among entities in a database.

Database Model

A framework that determines how data is stored, organized, and manipulated within a database, defining the logical structure and relationships between data elements.

Hierarchical Model

A data model where data is organized into a tree-like structure with one parent record and many children.

Network Model

A database model that uses a graph structure to represent data with nodes (records) and edges (sets) defining relationships, allowing many-to-many relationships.

Relational Database Model

A model that organizes data into tables (relations) consisting of rows (records) and columns (attributes).

Schema

The structure of a database that defines the name of tables, data fields with data types, relationships, and constraints.

DDL (Data Definition Language)

A subset of SQL used to create or modify the structure of database objects such as tables.

DML (Data Manipulation Language)

A subset of SQL used to manipulate data within the database, including statements like INSERT, UPDATE, and DELETE.

Database Security

The overall system of tools and processes used to protect sensitive data from both intentional threats and accidental misuse.

Normalization

The process of organizing data in a database to minimize redundancy and eliminate undesirable characteristics like insertion, update, and deletion anomalies.

Data Dictionary

A file containing meta-data, which is data about data, providing information about the database system such as location, size, tables, records, and user information.

Data Integrity

The accuracy, consistency, and reliability of data throughout its lifecycle, ensuring it is complete, accurate, and maintained to prevent unauthorized access, corruption, and loss.

Database Administrator (DBA)

A professional responsible for managing, maintaining, and securing a database system, ensuring its availability, optimal performance, and alignment with the organization's requirements.