I am working in a company that utilises many systems with their own databases. For example, the cafe has its own CAFE system with its own database (it could be postgresql). The Health Care system has its own database system (it could be MS SQL). The Transport booking has its own database system. And another system uses No-SQL database.
I am faced with a task of producing web-based management reports to allow managers to see key performance indicators on screen.
What would be the best way of accomplishing this?
I would perform cross database queries of the key performance indicators of the company. But I feel that there are things that I haven't taken into an account.
Has anyone done something similar and able to give me suggestions?