PostgreSQL

PostgreSQL, which most people shorten to Postgres, keeps a system's information in tables, exactly like MySQL and the rest of the family. It is free and open source, so any business may use it without paying. The difference is temperament, because Postgres is strict about what it accepts, and that strictness is why people choose it.

Ask it to save the thirty-first of February and it stores nothing near enough, because it stops and says no. Give it a name longer than the column allows and it refuses that too, rather than quietly trimming the end. Older databases took both without a word, so a shop found out only when a delivery address arrived cut in half. That first refusal is irritating, but it is exactly what you want in year three, when the money has to add up.

Postgres also does several jobs that would otherwise need extra software. It answers heavy questions across millions of rows, like last year's sales by branch, month and product, while the shop keeps serving customers. It measures distances on a map, so a system knows the branch nearest a customer. And it holds loose records beside the neat tables, which helps when one product type has fields the others do not. A system can therefore change shape without moving to another database, and moving database later is among the most expensive things a project does.

Here is the part almost nobody mentions. When Postgres changes or deletes a row it keeps the old version until a cleaning job passes, so the space is not returned straight away. That is why the file on a busy table can keep growing while the number of rows falls. The cleaning normally runs by itself, but when it falls behind, a disk fills on a quiet Sunday and the site stops. So ask who watches that, and how they would know.

The honest catch is money, because cheap shared hosting nearly always includes MySQL and often leaves Postgres out. Choosing it can therefore mean paying for a real server, as on Hostrena. Linkysoft picks Postgres when a system counts money, or when the reports matter as much as the daily screen. That means accounting, stock across several branches, and anything where a wrong number is a real loss. For a small booking site it is not worth the extra rent. Either way, ask which database your web application will use and why, because a good answer from Linkysoft, or anyone else, takes one sentence.