Why Low-level caching with Rails.cache? - Purpose & Use Cases

The Big Idea

What if your app could remember answers so it never asks the same question twice?

The Scenario

Imagine your web app fetches the same data from the database every time a user visits a page, even if the data hasn't changed.

This means slow page loads and extra work for your server.

The Problem

Manually repeating database queries wastes time and resources.

It makes your app slower and can frustrate users.

Also, writing code to remember and reuse data is tricky and easy to get wrong.

The Solution

Rails.cache lets you store data temporarily so your app can reuse it quickly without asking the database again.

This makes your app faster and reduces server load automatically.

Before vs After

✗ Before

user = User.find(1)
posts = Post.where(user_id: user.id).to_a

✓ After

posts = Rails.cache.fetch("user_1_posts", expires_in: 5.minutes) do
  Post.where(user_id: 1).to_a
end

What It Enables

You can speed up your app by reusing expensive data easily and reliably.

Real Life Example

A blog site caches the list of recent posts so visitors see pages load instantly without waiting for the database each time.

Key Takeaways

Manual repeated data fetching slows apps and wastes resources.

Rails.cache stores data temporarily to reuse it fast.

This improves speed and reduces server work effortlessly.