PostgreSQL

Yes, completely. PostgreSQL is distributed under the permissive PostgreSQL License: there are no license fees, subscriptions, or per-user charges, even for commercial projects. Your only cost is the server it runs on. By comparison, licenses for systems like Oracle or Microsoft SQL Server can run into thousands of dollars.

Both are popular open-source databases, but they differ. PostgreSQL follows the SQL standard more strictly, offers richer data types (JSON, arrays, geospatial data), and handles complex queries better. MySQL is owned by Oracle, while PostgreSQL is governed by an independent community. For simple sites either works; for complex or growing projects PostgreSQL is usually the stronger choice.

The main reasons are stronger JSON support, better performance on complex queries, stricter data-integrity guarantees, and fully independent governance (MySQL belongs to Oracle, so its direction depends on one company). In recent developer surveys such as Stack Overflow's annual survey, PostgreSQL has become the most-used database among professional developers.

Far more than most businesses will ever need. A single table can hold up to 32 terabytes, and a database has no practical size limit. Millions of orders and user records are routine workloads for PostgreSQL. A small or medium business site can run for years on an ordinary VPS without hitting scaling limits.

Yes - PostgreSQL has a dedicated JSONB type that stores, indexes, and quickly searches JSON documents (free-form key-value data). For many projects this eliminates the need for a separate NoSQL database like MongoDB: strictly structured tables and flexible JSON data can live in the same database.

ACID is a set of reliability guarantees: a transaction either completes fully or not at all. A simple example: when a customer places an order, the order must be recorded and the stock count reduced - ACID ensures you never end up with only one of the two happening. PostgreSQL is fully ACID-compliant, which is why it is widely used for payment and ordering systems.

Almost any project that works with dynamic data: e-commerce sites, booking and ordering systems, corporate sites with admin panels, CRMs, and mobile app backends. Only a purely static brochure site may not need a database at all. Since switching databases later is painful, choosing PostgreSQL from the start is a safe decision.

The database holds all of a site's live data - without backups, a server failure, a mistaken operation, or an attack could permanently destroy customer and order records. Setting up automated daily backups with tools like pg_dump is standard practice with PostgreSQL. Good practice also means storing copies on a separate server or cloud storage, so data survives even if the main server dies.

SQLite is a very simple file-based database, fine for prototypes and small projects with few simultaneous users. PostgreSQL runs as a dedicated server process and comfortably handles many concurrent users, complex queries, and large data volumes. For a real e-commerce or ordering system serving actual customers, PostgreSQL is the right choice; SQLite is better suited to testing and tiny internal tools.

SaytPro builds its dynamic projects on a Python/Django backend, and PostgreSQL is the database Django supports best and the one the industry considers most dependable. Databases run on SaytPro's own VPS infrastructure with regular automated backups. For clients that means zero licensing costs and data stored in a battle-tested system.