http://stackoverflow.com/questions/1152405/postgresql-is-better-using-multiple-databases-with-1-schema-each-or-1-database

I am new in schema concept for PostgreSQL.

For the above mentioned scenario, I was wondering

1. Why don't we use a single database (with default schema named public)
2. Why don't we have a single table, to store multiple users row?
3. Other tables which hold users related information, with foreign key point to the user table.

Can anyone provide me a real case scenario, which single database, multiple schema will be extremely useful, and can't solve by conventional single database, single schema.