Zusammenfassung der Ressource
Distributed databases
- What is it?
- A single logical database whose parts are
physically located in more than one place,
each location is accessible across a network
- Many organisations have offices and branches all over the world
- They have immediate access to their own information as
that information is what they'll be needing to access most of the time
- On the other had the central office needs to have an update version of the data as well
- With a single central databse, all queries and updates have to
travel across a network.
- This may cause a heavy load on the system
- This means if the central database breaks or the network goes down, the entire
organisation is affected
- With a distributed database, the central database is updated over night as a batch operation
- A supermarket stock system with many branches
- A travel company with branches across the country
- An international car dealer with dealers around the world
- partitioned database
- duplicated database