It depends on your personal preference. For production that you are not refreshing, it is convenient to install into the EBS database. For a dev/test instance frequently refreshed from production, it is convenient to host the schemas in a second database that is not refreshed, otherwise, you need to export the MDS and BIPLATFORM schemas before the refresh and import back every time.
Thanks for the update.
1)We have a single test database.In this case,if we install OBIEE ,can we export schemas before refresh and import it after refresh?
2)Or Do we need to create another database in existing test database and deploy those obiee schemas there?
We dont refresh PROD environment.In this case,can we install obiee here OR do we need to create a second database and install there?
i prefer my applications to have their own databases. Unless it's an application that goes along with the database. For instance, we have the Vertex schemas in the EBS database. So when ebs is cloned the vertex is cloned too.
We have Agile and AIA/PIP sharing a database.
It may save on licenses to have applications sharing a database.
If you have multiple applications sharing a database, when one has to go down for maintenance, so do the others. Something to consider.