To add a template to a disk group, use the ADD TEMPLATE clause of the ALTER DISKGROUP statement.
If the name of your new template is not listed in Table 5-6, then it is not used as a default template for database file types. To use the template, you must reference its name when creating a file.
When adding a template to a disk group, the attributes are optional. If no redundancy attribute is specified, then the value defaults to MIRROR for a normal redundancy disk group, HIGH for a high redundancy disk group, and UNPROTECTED for an external redundancy disk group. If you do not specify a striping attribute, then the value defaults to COARSE. If you do not specify a value for the primary or mirror region attributes, then the value defaults to COLD and MIRRORCOLD respectively.
Example 5-14 creates a new template named reliable for the normal redundancy disk group data.
Example 5-15 creates a new template named unreliable that specifies UNPROTECTED (no mirroring) for files.
Oracle discourages using unprotected files unless you have implemented hardware mirroring. The previous example is presented only to further illustrate how the attributes for templates are set.
Oracle Database SQL Language Reference for more information about the ALTER DISKGROUP...ADD TEMPLATE command