In the Database Configuration Assistant (DBCA) Storage Locations window, specify the type of storage you would like your database to use.
If you choose File System, your database files are managed by the file system of your operating system.
If you choose Automatic Storage Management (ASM), you place your data files in Oracle Automatic Storage Management (Oracle ASM) disk groups.
Then specify the locations for the Oracle database files. Select one of the following options:
Use Database File Locations from Template—This option instructs DBCA to use the directory information as specified in the template. Later, you can make modifications to database file names and locations.
Use Common Location for All Database Files—This option requires you to specify a new directory for the Oracle home. All the database files are created in this location. Later, you can make modifications to database file names and locations.
If you specify the Use Oracle Managed Files option, Oracle Database will directly manage operating system files comprising an Oracle database. You specify the default location, called a database area, for all your files. Oracle Database thereafter automatically creates and deletes files in this location, as required. When you select this option, you delegate the complete management of database files to the database. You no longer have to specify the file names, their location, or their sizes.
When you create a new database, it is important to configure the database so you can recover your data if a system failure occurs. Online redo log files contain a record of changes that were made to data files. Online redo log files are stored in online redo log groups. You must have at least two online redo log groups for your database. After the online redo log files in a group have filled up, the log writer process (LGWR) switches the writing of redo records to a new online redo log group. Oracle Database can automatically save the inactive group of online redo log files to one or more offline destinations, known collectively as the archived redo log (also called the archive log). The process of turning online redo log files into archived redo log files is called archiving.
Archiving can be performed only if the database is running in ARCHIVELOG mode. A group of online redo log files cannot be reused by the log writer (LGWR) process until the group is archived. If the database is running in NOARCHIVELOG mode, then when a group becomes inactive after the LGWR process switches to a new group, the inactive group is available for immediate reuse by the LGWR process.
The NOARCHIVELOG mode protects a database from instance failure but not from media failure. Only the most recent changes made to the database, which are stored in the online redo log files, are available for instance recovery. To restore a database operating in NOARCHIVELOG mode, you can use only entire database backups taken while the database is closed. Therefore, if you operate a database in NOARCHIVELOG mode, then back up the entire database at regular, frequent intervals.
The archiving of online redo log files has the following advantages:
A database backup, with online and archived redo log files, guarantees that you can recover all committed transactions if the operating system or hardware fails.
You can recover the database using a backup that was taken while the database was open and being used, if you have a copy of the archived log files that were written while the database was being backed up.
You can perform online tablespace backups, and use these backups to restore a tablespace following media failure.
You can keep a standby database current with its original database by continuously applying the original archived redo log files to the standby database.
Before you can archive the online redo log files, you must determine the destination to which you want to archive. Oracle recommends that the archive log be stored in a fast recovery area because it can simplify backup and recovery operations for your database. A fast recovery area is a location in which Oracle Database can store and manage files related to backup and recovery. It is distinct from the database area, which is a location for the current database files (data files, control files, and online redo log files).
When creating your database, you can select the following options:
Storage Type—Specify the type of storage you would like your database to use for recovery-related files. For more information, see "About Advanced Installation for Oracle Database".
Specify Fast Recovery Area—Select this option to specify a backup and recovery area and its directory location and size. You can use variables to identify standard locations.
Enable Archiving—Select this option to enable the archiving of database online redo log files, which can be used to recover a database. Selecting this option is the same as running the database in ARCHIVELOG mode.
Oracle recommends you select Enable Archiving. Selecting this option provides better protection for your database for software or hardware failure. If you do not select this option now, then you can enable ARCHIVELOG mode later. See "Configuring Your Database for Basic Backup and Recovery".