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PostgreSQL Glossary

Foreign Key

A constraint that establishes a link between data in two tables by referencing the primary key of another table. Example: A user_id foreign key in an orde…

Definition

A constraint that establishes a link between data in two tables by referencing the primary key of another table.

What Foreign Key Means in PostgreSQL

A constraint that establishes a link between data in two tables by referencing the primary key of another table.

Foreign Key appears frequently in production operations, architecture decisions, and troubleshooting workflows. Understanding this term helps teams reason about reliability, performance, and safe change management.

Why Foreign Key Matters

Teams that understand Foreign Key can make better decisions on database design, incident response, and release safety.

In modern PostgreSQL environments, this concept often connects directly to backup strategy, performance tuning, and operational confidence.

  • Improves decision quality for production operations
  • Reduces avoidable troubleshooting time
  • Strengthens reliability and recovery planning

Practical Example

A user_id foreign key in an orders table ensures every order belongs to a valid user in the users table.

Where To Learn More

You can explore deeper implementation patterns in the Vela articles library, review platform workflows in How Vela Works, and compare approaches in our PostgreSQL comparisons.

Related Glossary Topics

Full-Text Search ACID Atomicity Archiving (WAL Archiving) archive_command archive_mode BYOC (Bring Your Own Cloud) B-tree Index

Frequently Asked Questions

What is Foreign Key in PostgreSQL?
A constraint that establishes a link between data in two tables by referencing the primary key of another table.
Why is Foreign Key important?
Foreign Key matters because it directly affects how teams build, operate, and recover PostgreSQL systems in production.
Can you give a practical Foreign Key example?
A user_id foreign key in an orders table ensures every order belongs to a valid user in the users table.
How does Foreign Key relate to backup, recovery, or performance?
In most production deployments, Foreign Key influences one or more of these areas: data safety, restore behavior, and performance under load.
What should teams check first when implementing Foreign Key?
Start with clear operational goals, test in a non-production environment, and validate behavior with repeatable runbooks before relying on it in production.