@ranchofullstack — decision guide

Project ke liye SQL, MongoDB ya Redis — kaunsa lena chahiye?

Har developer alag bolta hai, is liye confusion normal hai. Yeh ek simple 3-question framework hai — isko follow karo, har project mein database ka decision 30 second mein clear ho jaayega.

QUESTION 01
Data ka structure fixed hai, aur records ke beech relations hain?
QUESTION 02
Har record ka shape alag-alag ho sakta hai — flexible, document-style data?
QUESTION 03
Speed sabse zyada matter karti hai — milliseconds mein response chahiye?

Decision Framework

save karo, har project mein kaam aayega
> project.data.analyze()
structured + relations important
SQL
MySQL, PostgreSQL — tables jo ek dusre se joined hote hain
flexible + document-style data
MongoDB
Har entry ka shape different — JSON jaisa format
speed-critical + temporary cache
Redis
RAM mein store, database se ~100x fast access

Side-by-side comparison

jab detail mein samajhna ho
 
SQL
MongoDB
Redis
Data model Tables, rows, columns — fixed schema Documents (JSON-like) — flexible schema Key-value pairs — RAM mein store hota hai
Best for Banking, e-commerce orders, inventory — jaha data consistency critical ho Social feeds, product catalogs, CMS — jaha structure change hota rahe Caching, sessions, leaderboards, OTP, rate-limiting
Relations Strong — JOINs ke saath multiple tables connect hote hain Weak — embedding ya manual references se handle hota hai None — sirf key ke against ek value
Query language SQL (SELECT, JOIN, WHERE...) MongoDB Query Language (find, aggregate...) Simple commands (GET, SET, EXPIRE...)
Persistence Permanent, disk-based Permanent, disk-based Temporary by default — optional disk snapshot
Popular options MySQL, PostgreSQL, SQLite MongoDB Atlas, self-hosted MongoDB Redis Cloud, Upstash, self-hosted Redis

Cost — free tier se shuru karo

student project ke liye 0 rupaye kaafi hain
Supabase (Postgres)
$0 /forever
  • 500 MB database, 2 free projects
  • 5 GB bandwidth/month
  • 1 week inactive rehne par project pause ho jaata hai
Paid plan ($25/month) tab lo jab production live ho aur pause afford na ho.
MongoDB Atlas (M0)
$0 /forever
  • 512 MB storage, shared RAM/vCPU
  • Koi time limit nahi — hamesha free
  • Real-world projects ke liye enough hai shuru mein
Dedicated plan (~$8+/month) tab lo jab 512 MB se zyada data ya guaranteed performance chahiye.
Redis Cloud
$0 /forever
  • 30 MB, single database, shared infra
  • 100 ops/sec, 30 connections cap
  • Sirf learning aur small projects ke liye
Essentials plan (from $5/month) tab lo jab real users hit karne lagein.
⚠️ Pricing time ke saath change hoti rehti hai — koi bhi service use karne se pehle unki official pricing page ek baar check kar lena.

Real projects → real choice

framework ko action mein dekho
E-commerce store
orders/inventory → SQL  |  product catalog → MongoDB  |  cart session → Redis
Orders mein strict consistency chahiye, products ka structure category ke hisaab se alag hota hai, cart ko fast access chahiye.
Social media app
user accounts → SQL  |  posts/comments → MongoDB  |  likes counter, feed cache → Redis
Auth data structured hota hai, posts ka format flexible, real-time counters ke liye speed chahiye.
Login system (koi bhi app)
user table → SQL  |  OTP / session token → Redis
User records structured, par OTP sirf kuch minute ke liye zinda rehta hai — Redis ka expiry feature perfect fit hai.
College/DSA practice project
bas ek database chahiye → SQL ya MongoDB (dono se seekho)
Beginner ho to dono ka free tier try karo — dono ka syntax alag feel karega, aur interview mein dono puchhe jaate hain.

Jab bhi confuse ho, bas yeh yaad rakho 👇

Data structured + relations important?→SQL
Data flexible + document-style?→MongoDB
Speed critical + temporary cache?→Redis