Oracle Database Architecture

Generally, Oracle RDBMS (Relation Database Management System) architecture consist of following components: Memory, processes, and files. The components are grouped into following:

1. Instance
   - Instance memory or System Global Area (SGA): Shared Pool (Libary Cache and Data Dictionary Cache), Database Buffer Cache, Redolog Buffer Cache, Java Pool, Large Pool.
   - Back ground process: PMON, SMON, DBWR, LGWR, CKPT, Others
   


2. Database
   - Datafiles
   - Control files
   - Redo log files
   


3. Other components
   - Other process: Server Process, user process
   - Other memory: Program Global Area (PGA)
   - Other files: Archived logs, parameter, and password files