Choose your DB Carefully - Evaluation Matrix
Old school guy here. Once upon a time we did software product evaluation matrixes that included technical support, cost of ownership(including testing environments) and vendor pricing reputation.
Experienced hands made few mistakes. Nowadays management sorts use Magic Circle Gartner reports to pick winners - or have some consultancy to make a recommendation - that had no financial consequences for them. Maybe only Walmart and Amazon fire those responsible for negative ROI outcomes.
Then Microsoft invented TOC, only cost of ownership, that never included yearly licence fee hikes, and optimum factors that worked for their marketing hype. But experienced evaluation people got the flick, as salesdroids targeted the decision makers with a budget. Game over.
Then Adabas/Natural DB started to Oracle their remaining declining customer base. One manager coined the expression bushranger tactics. IBM Mainframe users were astounded by vendor aggression. Most never bickered over price increases, when capacity management experts were made redundant.
Back to Oracle. Their tools for emergencies and business restoration were bullet proof. That won them business over DB2. People buying MS SQL Server never thought that far ahead. Then Oracle stated to do a Software AG trick - antagonise their reference sites.
Then came the Cloud - AWS and Cloudtastrophies. My tip to new players is never buy a product that allows auditors to set foot on site or steal your usage numbers. Greed never changes, so pick solutions where blackmail is less likely. OpenSource spinoffs are reliable enough.
If vendors won't licence or work with AWS, avoid them and pick another.