Replication of different databases to one master database
We need a solution to the following scenario:
We have 15 different sites all running their Oracle databases.
Each database is different and specific for each site..
We need a master database site where all 15 databases data need to be stored in real time.
Is there a configuration to suit this in Oracle?
Would it be possible to have only one database at the master site with 15 different users to represent the data for each of the different sites or will we need 15 different databases for each of the sites ?
Also what happens if the network was to fail between one of the sites and the master database?
Thanks in advance.