Module 8

Relational database

A database that stores data in tables with rows and columns.

Structured Query Language (SQL)

The language used to read and write data in relational databases.

Schema

The fixed structure of a relational database table (columns and data types).

Non-relational database (NoSQL)

A database with flexible records where items can have different attributes.

Managed service

A service where AWS handles many maintenance tasks like patching, backups, and high availability.

Unmanaged service

A setup where you manage scaling, fault tolerance, and availability yourself.

Amazon Relational Database Service (Amazon RDS)

A managed service that runs a relational database for you.

What AWS manages in Amazon RDS

Operating system patches, database engine patches, backups, scaling, and high availability.

What you manage in Amazon RDS

Application optimization and your data design.

Amazon RDS database engine

The database software you choose, like MySQL, PostgreSQL, or Oracle.

Multi-Availability Zone deployment (Multi-AZ)

A high availability setup with a primary database and synchronized standby in another Availability Zone.

Failover

Automatic switching to a standby system when the primary system fails.

Read replica

An extra copy of a database used mainly to handle read-heavy workloads.

Why use read replicas

To offload read queries and improve performance for read-heavy applications.

When to use Amazon RDS

When you need a traditional relational database with complex queries or transactions.

When not to use Amazon RDS

When you need extreme throughput, heavy sharding, or simple NoSQL-style lookups.

Amazon DynamoDB

A fully managed NoSQL database designed for fast performance at any scale.

DynamoDB table

A collection of items in Amazon DynamoDB.

DynamoDB item

A single record in an Amazon DynamoDB table.

DynamoDB attribute

A piece of data in an item, like a field.

Primary key

The required key used to uniquely identify and find items.

Partition key

The single key used to locate an item’s partition in DynamoDB.

Sort key

A second key used with a partition key to organize and query items.

Composite key

A partition key plus a sort key.

Query (DynamoDB)

A fast lookup operation that uses the primary key.

Scan (DynamoDB)

A slower search that checks items for matching attributes.

Why DynamoDB is fast

It runs on solid state drives and is built for low-latency scaling.

When to use DynamoDB

When you need high scale, fast performance, and flexible data structures.

Amazon Redshift

A managed data warehouse used for analytics and large-scale reporting.

Data warehouse

A system designed for analyzing large amounts of data and running complex analytic queries.

Columnar storage

A storage method that stores data by columns, improving analytic query speed.

Parallel processing

Using multiple resources at the same time to speed up large queries.

Amazon Aurora

An Amazon-built relational database compatible with MySQL and PostgreSQL.

Aurora high availability

Stores multiple copies of data across multiple Availability Zones.

Aurora backups

Uses continuous backups to Amazon Simple Storage Service (Amazon S3).

Aurora read replicas

Supports many read replicas to scale read performance.

Best database choice for analytics

Amazon Redshift.

Best database choice for managed relational

Amazon RDS or Amazon Aurora.

Best database choice for managed NoSQL

Amazon DynamoDB.

Best database choice for full control

Run a database on Amazon Elastic Compute Cloud (Amazon EC2).