OCP 1Z0 053 120

120.You are managing an Oracle Database 11g instance and an Oracle Database 10g instance on the 
same machine. Both instances use the ASM instance as storage. Which statement regarding the ASM 
disk group compatibility attributes are true in this scenario? (Choose all that apply.) 
A. The database-compatibility version settings for each instance must be greater than or equal to the 
RDBMS compatibility of all ASM disk groups used by that database instances. 
B. RDBMS compatibility and the database version determines whether a database instance can mount 
the ASM disk group. 
C. The RDBMS compatibility settings for a disk group control the format of data structures for ASM 
metadata on the disk. 
D. ASM compatibility controls which features for the ASM will be enabled. 
Answer: ABD


http://docs.oracle.com/cd/E11882_01/server.112/e18951/asmdiskgrps.htm#OSTMG94137

Overview of Disk Group Compatibility

Advancing the disk group compatibility settings enables you to use the new Oracle ASM features that are available in a later release. For example, a disk group with the disk group compatibility attributes set to 11.2 can take advantage of new Oracle 11g release 2 (11.2) features, such as Oracle ASM volumes in disk groups and Oracle ASM File Access Control. See Table 4-3 for the features enabled for combinations of compatibility attribute settings.

The disk group compatibility feature also enables environments to interoperate when they use disk groups from both Oracle Database 10g and Oracle Database 11g. For example, disk group compatibility settings that are set to Oracle Database 10g enable an Oracle 10g client to access a disk group created with Oracle ASM 11g.

The disk group attributes that determine compatibility are COMPATIBLE.ASM, COMPATIBLE.RDBMS. and COMPATIBLE.ADVM. The COMPATIBLE.ASM and COMPATIBLE.RDBMSattribute settings determine the minimum Oracle Database software version numbers that a system can use for Oracle ASM and the database instance types respectively. For example, if the Oracle ASM compatibility setting is 11.2, and RDBMS compatibility is set to 11.1, then the Oracle ASM software version must be at least 11.2, and the Oracle Database client software version must be at least 11.1. The COMPATIBLE.ADVM attribute determines whether the Oracle ASM Dynamic Volume Manager feature can create an volume in a disk group.

When you create a disk group, you can specify the disk group compatibility attribute settings in the CREATE DISKGROUP SQL statement. The ALTER DISKGROUP SQL statement can update the compatible attribute settings for existing disk groups. If not specified when using the CREATE DISKGROUP SQL statement, 10.1 is the default setting for both the COMPATIBLE.ASM and COMPATIBLE.RDBMS attributes for Oracle ASM in Oracle Database 11g. The COMPATIBLE.ADVM attribute is empty if it is not set.