Oracle DB is the "do everything database", it has nearly every DB paradigm "all-in-one", and is an extremely well-tested and predictable product. It often comes bundled with entire vertical solutions like "Bank in a Box" or "CRM", and with a contract including SLAs, so you're covered if/when things go wrong (as long as you pay $$$).
There are a lot of pros and cons, too many to enumerate on a Thursday night before dinner.
Bottom line: Oracle DB can be super expensive, but if you pay [enough] then Oracle will give you endless support to ensure you are successful (so you can keep paying them). They have some top-notch in-house expertise and there are good reasons large businesses keep paying the bill and renewing contracts (some part lock-in, other part solving real business needs).
Personally, I really like Postgres and SQLite. But they're no Bank-in-Box, and the support is comprised of "https://google.com/?q=...".
The reason Oracle makes so much money is not because they are best for some definition of best, but:
1. Lock in -> A database change is hard to do even for extremely focused tech companies. For companies whose core business is not technology, it might not even make sense to bother.
2. They expanded beyond the DB to acquire several companies like Peoplesoft and Netsuite and companies needing these inevitably turn to Oracle database.
Don't get me wrong, oracle has tons of Optimisations packed into it, but there is nothing which makes it the best database, or even an unambiguous top 3 databse product.
Just to back this up - it took Amazon years to complete the project of moving off Oracle, and this is a company that had already built and/or hosted myriad database platforms in AWS. They had no lack of expertise.
> We migrated 75 petabytes of internal data stored in nearly 7,500 Oracle databases to multiple AWS database services including Amazon DynamoDB, Amazon Aurora, Amazon Relational Database Service (RDS), and Amazon Redshift.
https://aws.amazon.com/blogs/aws/migration-complete-amazons-...
Once you’ve introduced the Oracle, unless you firewall these people, those people end up “infecting” other processes. Oracle pays salespeople more to cross-sell their colleagues, and your Oracle SMEs start seeding Oracle shit wherever they can. You inevitably violate a license agreement, and then end up buying more Oracle shit as a penance. And the cycle continues.
Once infected, it’s difficult to cure. You need the rare combo of strong IT and business leadership and hands on, aggressive legal over a period of years. While battling, the vendor will do whatever they can to undermine that leadership and reward allies.
https://www.dbmaestro.com/blog/database-automation/postgresq...
Perhaps 25 years ago it was true.
Fixing Oracle bugs, it's like a knightmare.
