Definition - What does Virtual Database mean?
Virtual databases are also known as federated databases.
Techopedia explains Virtual Database
Each of the combined databases in the system is completely self-sustaining and functional, and is able to function on its own without depending on other existing databases. When an application requests to access a virtual database, the system figures out which of the databases contain the data being requested by the user and passes on the request to that database. The most important and challenging part of building a virtual database is building a universal data model, which serves as the map or guide to every source of data within the company.
By incorporating several databases under a centralized container, a virtual database offers a lot of benefits. One of its key advantages is that it serves as an alternative merging technique for multiple databases, a rather difficult task to do for most end-users. It can also assist developers in avoiding the tight connection of applications by removing vendor and schema lock-in. Applications just need to be connected to the virtual database to be able to access multiple databases.