The database under your app: Firestore or MySQL and PostgreSQL

This is one comparison where both options are tools VS Tech Builders works with. We built the Pirandai Kadai store on Firebase, and PostgreSQL and MySQL are both in the stack we use for management systems. The right choice depends on the shape of your data and how it will be read, not on which technology is fashionable this year.

Fit: live screens or ledgers

Firestore stores data as documents, and apps listen to them. When a delivery person for a water-can supplier in Salem marks an order delivered, the customer's app and the dispatcher's screen update the moment the phone syncs, even if there was no signal at the doorstep. SQL databases keep data in related tables: invoices, invoice lines, customers, payments. When a wholesale distributor asks for outstanding by salesman, ageing by customer and GST by rate for the month, SQL answers each in one query. Firestore has counting and summing queries but no joins, so reports like these must be planned in advance with duplicated or pre-calculated data.

Cost over five years: usage billing or a fixed server

Firestore charges for what users do: every document read, write and delete, plus storage and network transfer, once the free daily allowance is used up. A small app can run for years at almost no cost. The risk lies in design. A dashboard that reads ten thousand documents each time it opens costs money every time anyone opens it. MySQL and PostgreSQL cost whatever the server costs, every month, whether ten screens open or ten thousand. For a reporting-heavy system with steady use, that predictability is worth a great deal.

Ownership and lock-in

Both can be owned in the sense that matters: your project, your account, your data, exportable at any time. The lock-in differs. Firestore is a Google service, and leaving it means rewriting how the app reads and writes data. PostgreSQL and MySQL are open source and run anywhere: Hostinger, AWS, Google Cloud or a server in your office. Whichever we choose, the cloud accounts and code are transferred into your name at handover.

Speed to start

Firebase is quicker off the mark. Authentication, database, file storage and hosting exist the moment the project is created, and access control is written as security rules rather than built from scratch. A SQL-backed system needs an API layer and a server before the first screen works. That adds time at the start but gives business rules a proper home on the server, which matters once the rules become complicated. Our Firebase app development page describes the faster route in more detail.

Integrations

Firebase connects naturally to Google's ecosystem: push notifications, analytics, Cloud Functions that receive webhooks from Razorpay or WhatsApp, and an export to BigQuery for analysis. Server-side functions need the pay-as-you-go plan, so budget for that from the start. SQL databases connect to almost anything that reads SQL: Excel, Power BI, Metabase, accounting exports and other systems' APIs. If your business lives in spreadsheets and reports, a relational database such as PostgreSQL is the more natural neighbour.

Support and day-to-day running

Firestore has no server to patch, and it scales without anyone noticing. The ongoing work is watching usage, reviewing security rules and adding indexes as queries change. A SQL database needs version updates, tested backups and an eye on disk and memory, handled by your developer or by a managed service. Neither is maintenance-free; they simply need different kinds of care.

Scaling under load

Firestore scales with traffic automatically, which suits apps with sharp peaks such as festival-season orders. SQL databases scale through larger servers and read replicas and can carry very large businesses, but you plan each step yourself. For most business systems, neither database's ceiling is the real constraint; the quality of the data model is. Apps that must keep working through patchy signal benefit from offline-first app development on either database.