Cost optimization (read/write reduction) in Firebase - Mini Project: Build & Apply

Cost Optimization with Firebase Read/Write Reduction

📖 Scenario: You are managing a Firebase Realtime Database for a small online store. You want to reduce the number of reads and writes to save costs while keeping the data accurate and up to date.

🎯 Goal: Build a Firebase Realtime Database structure and rules that minimize unnecessary reads and writes by using data denormalization and efficient queries.

📋 What You'll Learn

Create a Firebase Realtime Database structure with products and orders

Add a configuration variable to limit the number of product details fetched

Write a query to fetch only the top N products based on the configuration

Add security rules to allow read/write only to necessary paths

💡 Why This Matters

🌍 Real World

This project simulates managing a Firebase database for an online store where cost control is important by reducing unnecessary database operations.

💼 Career

Understanding how to optimize Firebase reads and writes is valuable for roles like Cloud Engineer, Backend Developer, and DevOps Specialist working with serverless databases.

1

Create initial Firebase data structure

Create a Firebase Realtime Database JSON structure with a products node containing exactly these three products: product1 with name "Laptop" and price 1200, product2 with name "Phone" and price 800, and product3 with name "Tablet" and price 600.

Firebase

{
  "products": {
    // Your code here
  }
}

Need a hint?

Use a JSON object with a products key and add three product objects inside.

2

Add configuration variable for product fetch limit

Add a configuration variable called maxProductsToFetch and set it to 2 inside a new config node in the Firebase JSON structure.

Firebase

{
  "products": {
    "product1": {"name": "Laptop", "price": 1200},
    "product2": {"name": "Phone", "price": 800},
    "product3": {"name": "Tablet", "price": 600}
  },
  "config": {
    // Your code here
  }
}

Need a hint?

Add a new config object with the variable inside.

3

Write a query to fetch limited products

Write a Firebase Realtime Database query in JSON format under a new queries node that fetches products ordered by price descending and limits the results to the value of maxProductsToFetch. Name this query topProducts.

Firebase

{
  "products": {
    "product1": {"name": "Laptop", "price": 1200},
    "product2": {"name": "Phone", "price": 800},
    "product3": {"name": "Tablet", "price": 600}
  },
  "config": {
    "maxProductsToFetch": 2
  },
  "queries": {
    // Your code here
  }
}

Need a hint?

Use orderBy with price and limitToLast with the config value.

4

Add Firebase security rules for read/write access

Add Firebase Realtime Database security rules that allow read access only to the products and config nodes, and allow write access only to the config node. Deny all other access.

Firebase

{
  "rules": {
    // Your code here
  }
}

Need a hint?

Set .read and .write rules explicitly for each node.