we have hr system for government that serves about 50 governmental organizations the company who created the system want to change the structure of the current system which is one database serving all the organizations to the following:
1)central shared database that have shared data used by all the organizations like look ups tables.
2)database for each organization with the same database structure but the data will be different from organization to organization (for example ministry of health will have the hr data for its own employees and ministry of internal affaires will have its own employees data ). so the system will change from one single database serving 50 organizations to 1 shared database + 50 databases having the same structure (tables, tablespaces, datafiles and etc.. ) which is a total of 51 databases.
the system is not that large for example the size of dump is 50GB and the total size is about 200GB for the datafile or maybe less also the number of application users is about 2000 users and they are not concurrent. i think the company is doing it on the fishy way or they are trying to make the management think that they have a large system.
the questions are the following:
1) is the best practice to change the system structure from one Database to multiple Databases doing the same thing but with different data.
2) if we go with what is the maximum number of databases (oracle 11g) that can be used on single machine.
3)is it a waist of resources specially taking the redundancy solution for hight availability.