Creating Oracle ASM Files Using a Default File Location for Disk Group Specification

Using the Oracle Managed Files feature for operating system files, you can specify a directory as the default location for the creation of data files, temporary files, redo log files, and control files. Using the Oracle Managed Files feature for Oracle ASM, you can specify a disk group, in the form of an incomplete Oracle ASM file name, as the default location for creation of these files, and additional types of files, including archived log files. As for operating system files, the name of the default disk group is stored in an initialization parameter and is used whenever a file specification (for example, DATAFILE clause) is not explicitly specified during file creation.

The following initialization parameters accept the multiple file creation context form of Oracle ASM file names as a destination:

  • DB_CREATE_FILE_DEST

    Specifies the default disk group location in which to create data and temp files.

  • DB_CREATE_ONLINE_LOG_DEST_n

    Specifies the default disk group location in which to create redo log and control files.

  • DB_RECOVERY_FILE_DEST

    Specifies a default disk group for a fast recovery area that contains a copy of the control file and redo log files if this parameter is specified and DB_CREATE_ONLINE_LOG_DEST_n and CONTROL_FILES are not specified.

  • CONTROL_FILES

    Specifies a disk group in which to create control files.

The following initialization parameters accept the multiple file creation context form of the Oracle ASM file names and Oracle ASM directory names as a destination:

  • LOG_ARCHIVE_DEST_n

    Specifies a default disk group or Oracle ASM directory as destination for archiving redo log files

  • LOG_ARCHIVE_DEST

    Optional parameter to use to specify a default disk group or Oracle ASM directory as destination for archiving redo log files. Use when specifying only one destination.

  • STANDBY_ARCHIVE_DEST

    Relevant only for a standby database. It specifies a default disk group or Oracle ASM directory that is the location of archive logs arriving from a primary database. Not discussed in this book. This parameter has been deprecated. See Oracle Data Guard Concepts and Administration.

The following CREATE TABLESPACE SQL statement illustrates how an Oracle ASM file, in this case a data file, might be created in a default disk group. This example assumes that the DB_CREATE_FILE_DEST initialization parameter has been set to +data.

SQL> CREATE TABLESPACE mytblspace;

Oracle ASM automatically creates and manages the data file for mytblspace on Oracle ASM disks in the disk group data. File extents are stored using the attributes defined by the default template for a data file.

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