Postgresql Multiple Database VS Multiple Schemas

Question

We are in the process of building a cluster for our hosted services at work, the final product will be used to host multiple separate services. We are in the middle of deciding on how we want to setup our databases. We are running a postgresql database server which all services in the cluster will use. The debate right now is whether to give each service its own schema in a single database or to give each service its own database.

We just aren't sure which is the better solution for us. None of our services have a common structure and data does not need to be shared. What we are more concerned about is ease of use.

Here's what we care most about, we are really hoping for an objective vs opinion based answer.

Backups

Disaster recovery - all services vs individual

Security between services

Performance

For some additional information, the cluster is hosted within AWS with our database being an RDS instance.

Answer 1

This is what PostgreSQL official docs says:

Databases are physically separated and access control is managed at the connection level. If one PostgreSQL server instance is to house projects or users that should be separate and for the most part unaware of each other, it is therefore recommendable to put them into separate databases. If the projects or users are interrelated and should be able to use each other's resources they should be put in the same database, but possibly into separate schemas. Schemas are a purely logical structure and who can access what is managed by the privilege system.

Source: http://www.postgresql.org/docs/8.0/static/managing-databases.html