Database Modeling and Database Systems

These flashcards cover essential terms and definitions related to database modeling, management systems, and SQL.

Database Management System (DBMS)

A software system that uses a standard method of cataloging, retrieving, and running queries on data.

Entity Relationship Model (ERM)

A diagram that shows the relationships between data entities in a database.

Primary Key

An attribute or set of attributes that uniquely identifies a record in a table.

Foreign Key

An attribute in one table that links to the primary key in another table to establish a relationship.

Normalization

The process of organizing data to minimize redundancy and improve data integrity.

Relational Database

A database that stores data in interconnected tables using a relational model.

SQL (Structured Query Language)

A standard programming language used to manage and manipulate relational databases.

NoSQL

A type of database that provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases.

ACID Properties

A set of properties that guarantee that database transactions are processed reliably: Atomicity, Consistency, Isolation, Durability.

Join

A SQL operation used to combine rows from two or more tables based on a related column.

Transaction

A sequence of operations performed as a single logical unit of work that must be either entirely completed or aborted.

NULL Value

A marker used in databases to indicate that a data value does not exist in the database.

Data Integrity

The accuracy and consistency of stored data.

Composite Key

A primary key composed of two or more columns in a table.

Unique Constraint

A rule that ensures all values in a column are different from each other.

Entity Set

A collection of similar types of entities.

Subquery

A query nested inside another query in SQL.

Data Schema

The structure of a database, defined by the way data is organized and how the relations among them are handled.

Cardinality

The uniqueness of data values contained in a particular field (attribute) of a table.

Data Types

The classification of data items, specifying what type of value can be stored in a column.

Referential Integrity

A property that ensures that relationships between tables remain consistent.

Join Types

Different methods to combine rows from multiple tables, such as INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN.