Your quote says PostgreSQL. That's the line holding every record you own.

Tables, rows, and a promise about half-finished work

Picture a spreadsheet with rules it enforces. A table holds one kind of thing: customers, or invoices, or work orders. A row is one of them, and each column decides in advance what it will accept.

The relational part is the pointing. An invoice doesn't repeat the customer's address inside itself. It points at the customer, who exists once. Change that address and every invoice pointing at it is now correct, because there was only one copy to change.

The second half rarely makes it into a proposal. Taking a payment and marking the order paid are two separate writes. A relational database wraps them into one unit and promises that either both happen or neither does, even if the power cuts between them. You don't end up with a charged card and no order. When somebody says a database is ACID compliant, that promise is the claim.

Boring and correct is the whole point

PostgreSQL began as a research project at Berkeley in the 1980s and took on SQL along with its current name in the mid-nineties. It was built by people arguing about correctness rather than by a company shipping against a quarter, and it still isn't owned by anybody. No vendor, no seat count, no licence to renegotiate. Some other databases are open source in the same sense only until the company behind them changes the licence.

That shows up as constraints, which are rules you hand to the database rather than to the application. An invoice must belong to a customer that exists. An email address can appear once. A quantity can't go negative. Set those and the database refuses bad data even when the code writing it has a bug, and code eventually has a bug.

It's also the answer everybody already gives. PostgreSQL has sat at the top of the most-used-database list in recent Stack Overflow developer surveys, and that matters commercially rather than technically. You can hire for it, get three firms to quote the same job, and run it on every cloud there is. A major version arrives yearly and is supported for about five, which is the right pace for the thing holding your records.

It has absorbed most of the reasons to add a second database

Projects used to collect databases. One for the records, one for search, one for anything that didn't sit neatly in a table. Much of that has quietly stopped being necessary.

PostgreSQL stores JSON documents and can index inside them, so the variable part of your data lives in the same table as the strict part. Full-text search is built in. Extensions, which are bolt-on modules that add capability without anyone forking the software, cover geographic data, the vector storage AI features want, and time-series work. Most managed hosts offer the common ones behind a checkbox.

A dedicated search engine still handles typos and relevance tuning better, and a dedicated cache is faster for data rewritten constantly that doesn't need to survive a restart. The question is whether you're past the volume where that shows. Most businesses aren't, and the way to find out is to start with one and add the second when something measurable says to.

Where it stops

None of this is a reason to avoid it. Knowing where the boundary sits beats discovering it.

It wants your data to have a shape. Not a rigid one, since JSON columns absorb the parts that vary, but if every record genuinely has different fields and the shape changes weekly, you'll spend the project fighting a tool that's trying to help.

It scales in two directions easily and one hard. A bigger machine is a settings change. Read-only copies, so reports don't slow the application, are built in. Splitting writes across many machines needs extra tooling and is a project rather than a setting. Few businesses reach that point.

Analytics is the common mistake. PostgreSQL stores a row at a time, right for looking up one order and wrong for summing one column across a billion. The version that actually bites is smaller: a reporting dashboard on the same database the application uses, slowing checkout every time somebody opens it.

Somebody has to run it, and that's a staffing question

The software costs nothing. You pay for a computer to run it on, and how you buy that computer decides how much of this becomes a job.

Managed hosting is the default now, and for most businesses it should be. Every major cloud sells PostgreSQL and so do a handful of specialists. What you're buying is that patching, backups, failover and upgrades belong to somebody else.

What stays yours either way is the schema, the indexes, and noticing on the morning a query got slow. That isn't a full-time role for most businesses. It's one reachable person, and "the developer who built it" stops being that answer the moment the engagement ends.

Run it yourself and you inherit the rest. Every connection is a separate process on the server, so anything opening a lot of them needs a pooler in front. Old row versions sit there until a background job clears them, invisible until a busy table outpaces it. Neither is exotic, and both want somebody who has met them before.

Ask who that person is before anyone starts building.