Understand the database components that Oracle Database Configuration Assistant (Oracle DBCA) creates.

• About Tablespaces and Data Files
  For both single-instance and cluster database environments, Oracle Database is divided into smaller logical areas of space known as tablespaces.
• About Control Files
  The database is configured with two control files that must be stored on shared storage.
• About Online Redo Log Files
  Each database instance must have at least two online redo log files.