Overview The Oracle server uses many memory components, background processes, and file structures for its backup and recovery mechanism. This lesson reviews the concepts presented in the Oracle9i Database Administration Fundamentals I course, with an emphasis on backup and recovery requirements. Oracle Instance An Oracle instance consists of memory areas (mainly System Global Area [SGA]) and background processes, namely PMON, SMON, DBWn, LGWR, and CKPT. An instance is created during the nomount stage of the database startup after the parameter file has been read. If any of these processes terminate, the instance shuts down | Instance and Media Recovery Structures Objectives After completing this lesson, you should be able to do the following: Describe the Oracle processes, memory structures, and files relating to recovery Identify the importance of checkpoints, redo log files, and archived log files Describe ways to tune instance recovery Overview Database Datafile 1 Datafile 2 Datafile 3 Control file Redo log file 1 Redo log file 2 Instance SGA Redo log buffer Database buffer cache Large Pool Java Pool Shared pool Data dict. cache Shared SQL and PL/SQL ARCn User process Server process PGA Parameter file Password file Archived log files PMON DBWn SMON LGWR CKPT Overview The Oracle server uses many memory components, background processes, and file structures for its backup and recovery mechanism. This lesson reviews the concepts presented in the Oracle9i Database Administration Fundamentals I course, with an emphasis on backup and recovery requirements. Oracle Instance An Oracle instance consists of . | Instance and Media Recovery Structures Objectives After completing this lesson, you should be able to do the following: Describe the Oracle processes, memory structures, and files relating to recovery Identify the importance of checkpoints, redo log files, and archived log files Describe ways to tune instance recovery Overview Database Datafile 1 Datafile 2 Datafile 3 Control file Redo log file 1 Redo log file 2 Instance SGA Redo log buffer Database buffer cache Large Pool Java Pool Shared pool Data dict. cache Shared SQL and PL/SQL ARCn User process Server process PGA Parameter file Password file Archived log files PMON DBWn SMON LGWR CKPT Overview The Oracle server uses many memory components, background processes, and file structures for its backup and recovery mechanism. This lesson reviews the concepts presented in the Oracle9i Database Administration Fundamentals I course, with an emphasis on backup and recovery requirements. Oracle Instance An Oracle instance consists of memory areas (mainly System Global Area [SGA]) and background processes, namely PMON, SMON, DBWn, LGWR, and CKPT. An instance is created during the nomount stage of the database startup after the parameter file has been read. If any of these processes terminate, the instance shuts down. Overview (continued) Memory Structures Background Processes The User Process The user process is created when a user starts a tool such as SQL*Plus, Oracle Forms Developer, Oracle Reports Developer, Oracle Enterprise Manager, and so on. This process might be on the client or server, and provides an interface for the user to enter commands that interact with the database. Overview (continued) The Server Process The server process accepts commands from the user process and performs steps to complete user requests. If the database is not in a shared server configuration, a server process is created on the machine containing the instance when a valid connection is established. Oracle Database An Oracle .
