Duplicate A Local Database

You can quickly create a new database instance that is a duplicate of another database. If the existing database is local, you don't need to dump and restore. Instead you can use the createdb command that comes with Postgres:

$ createdb -O ownername -T originaldb newdb

This creates a new database called newdb using originaldb as a template (-T). This will include the entire schema and data of the original database. The -O flag allows you to specify the owner of the database. Since this is local, you probably want your primary unix user as the owner.

source