A Developer’s Guide to SQLite

SQLite

What Is SQLite?

SQLite is a serverless, self-contained SQL database engine.

Unlike PostgreSQL or MySQL, which run as separate server processes, SQLite stores your entire database in a single .db file on disk.

  • No setup
  • No configuration
  • Just include it in your app and start querying

Example:

sqlite3 mydatabase.db

That’s it. You’re ready to go.

How SQLite Works?

SQLite reads and writes directly to a single file.

Every table, index, and row of data exists inside that one file.

When your app executes a query:

  • SQLite opens the file
  • Locks it (to avoid concurrent writes)
  • Executes the SQL command
  • Updates the data
  • Releases the lock

This is simple and reliable — but it also introduces limitations for concurrent writes (more on that soon).

Is SQLite Safe?

Property Meaning
Atomicity A transaction completes fully or not at all
Consistency Data always remains valid
Isolation Transactions don’t interfere with each other
Durability Data persists even after crashes or power failures

So technically, SQLite is as safe as PostgreSQL or MySQL — for a single user or small app.

Where SQLite Excels

  • Prototyping and small apps
    No server needed — perfect for testing, small websites, or internal tools.
  • Embedded systems
    Used in browsers (like Chrome), phones (Android), and IoT devices.
  • Local caching or offline storage
    You can use SQLite as a local cache even in large apps that sync data with a remote API.
  • Developer convenience
    It’s extremely easy to set up and deploy. No “database connection” step — just point to a file.

Where SQLite Struggles

Here’s where you need to think twice before using SQLite in production.

1. Limited Write Concurrency

SQLite allows only one write operation at a time.
If 10 users try to update data simultaneously, 9 will wait until the first finishes.

That’s because SQLite locks the entire database file during a write.

For small-scale apps, it’s fine. But in high-traffic apps (like multi-user dashboards or APIs), this becomes a bottleneck.

2. Scaling and Performance

SQLite runs inside your app process. There’s no database server to distribute workload or balance traffic. So if your app scales horizontally (multiple instances), each instance would have its own copy of the SQLite file, and they’d quickly go out of sync.

PostgreSQL or MySQL, on the other hand, run as servers — multiple clients can connect, and the DB engine manages concurrent reads/writes safely.

3. Missing Features for Big Apps

SQLite is lightweight — but that also means:

  • No user permissions or roles
  • No background daemons
  • No stored procedures
  • No built-in replication or clustering
  • Limited full-text search

It’s not designed for distributed systems or complex data workflows.

Understanding MVCC (and Why It Matters)

Databases like PostgreSQL and MySQL (InnoDB) use a system called MVCC – Multi-Version Concurrency Control.

Here’s what it does:

  • When multiple users write or read the same data, the DB creates versions of each row.
  • Each transaction works on its own version — no blocking.
  • When one finishes, it merges changes safely.

This allows multiple concurrent reads and writes without data corruption.

SQLite doesn’t use full MVCC; it handles concurrency through file-level locking — simple but less flexible.

Who Handles What: Server vs Database

Role Responsible for
Server (e.g., Apache, Nginx, Node.js) Handles HTTP requests, routing, APIs, and client communication
Database (e.g., SQLite, PostgreSQL, MySQL) Handles data storage, querying, and transactions

In a Node.js + SQLite setup:

  • Node.js (your runtime) receives a request (say, update a user)
  • Your backend code runs an SQL query through SQLite
  • SQLite handles the transaction and writes to the .db file

In PostgreSQL:
  • The DB server runs separately
  • Your app connects via TCP to execute queries
  • PostgreSQL manages users, background workers, caching, and MVCC

So the database itself — not your server — ensures ACID safety, transactions, and concurrency.

Can You Migrate Later?

Yes, and this is a smart strategy for startups and solo developers:

  • Start with SQLite (super fast to develop)
  • Once traffic grows → migrate to PostgreSQL or MySQL

Most ORMs (like Prisma, Drizzle ORM, Sequelize, etc.) let you switch the database backend without rewriting all your code — only minor configuration changes.

But be careful with:

  • SQLite-specific SQL features (like certain date functions)
  • File path management
  • Transactional edge cases

So yes — you can start with SQLite and move later. Just plan for it.

TL;DR — Should You Use SQLite in Production?

Use Case SQLite PostgreSQL / MySQL
Hobby projects ✅ Excellent Overkill
Desktop / mobile apps ✅ Excellent Not needed
Small websites (low traffic) ✅ Okay Optional
Medium or large web apps ⚠️ Risky ✅ Recommended
High write concurrency ❌ No ✅ Yes
Multi-server deployment ❌ No ✅ Yes
Data integrity ✅ Yes ✅ Yes

SQLite is a real database engine — safe, ACID-compliant, and battle-tested.

It’s ideal for:

  • Simple web apps
  • Internal tools
  • Single-user applications
  • Prototypes or MVPs

But when your app starts getting real users, concurrent writes, and scaling needs, move to PostgreSQL or MySQL. They’re built for multi-user, concurrent, and distributed workloads.


Thank You!