Relational Database Management Systems (RDBMS) Knowledge

Contents

• Overview
• Core Idea
• Key Concepts
  • Relational Algebra
  • Relational Design Theory and Database Normalization
  • Structured Query Language (SQL)
• RDBMS Terminology

Overview

A Relational Database Management System (RDBMS) is the software surrounding a database that allows for a relational model to be configured as the database schema and for queries and operations to be run safely and consistently.

Core Idea

Create a suite of software to manage an underlying database, provide an interface for users and applications, and ensure that key properties like safety, reliability, and persistence are maintained.

Key Concepts

Relational Algebra

Refer to Relational Algebra Knowledge article.

Relational Design Theory and Database Normalization

The Boyce-Codd Normal Form (BCNF) is a form of database that removes all redundancy based on functional dependencies. Functional dependencies represent a constraint between attributes of a relation such that the set on the left hand side uniquely identifies the right hand side.

Structured Query Language (SQL)

Refer to Structured Query Language (SQL) Knowledge article.

RDBMS Terminology

atomic type

an indivisable kind of data; e.g. a boolean

attributes

the columns; or the divisions of data kinds

instance

the data stored in the relations (which are described by the schema) at any given point

key

attribute whose value is unique in each tuple (note: could also be a set of attributes)

relations

the tables; or the structures that store related data

schema

structural description of relations; the name, the attributes, and the types of those attributes

structured type

a composed kind of data, possibly user-defined; e.g. a PersonType

tuples

the rows; or records of data across attributes

type

the domains; or the kind of data stored in each attribute