How to determine which diskgroups a database is using

Question

We want to be able to determine which diskgroups a database is using. We have been using the following query which works but only if the database has open or had open the "right set of files" recently --
SQL> select dg.name from v$asm_diskgroup_stat dg, v$asm_client c where dg.group_number = c.group_number and c.db_name = 'MYDB';
If no archived logs have been generated in a while then the diskgroup that contains the FRA will no be listed in this query. We can cause the FRA diskgroup to show up if we archive the current log. Here is an example.
SQL> select * from v$asm_client;
GROUP_NUMBER INSTANCE_NAME
DB_NAME  STATUS
SOFTWARE_VERSION
COMPATIBLE_VERSION
            5 +ASM
DBI03    CONNECTED
11.2.0.3.0
11.2.0.0.0
SQL> alter system archive log current;
System altered.
SQL> select * from v$asm_client;
GROUP_NUMBER INSTANCE_NAME
DB_NAME  STATUS
SOFTWARE_VERSION
COMPATIBLE_VERSION
            5 +ASM
DBI03    CONNECTED
11.2.0.3.0
11.2.0.0.0
GROUP_NUMBER INSTANCE_NAME
DB_NAME  STATUS
SOFTWARE_VERSION
COMPATIBLE_VERSION
            7 +ASM
DBI03    CONNECTED
11.2.0.3.0
11.2.0.0.0
Notice how diskgroup "7" shows up after the log is archived? It appears that the instance for diskgroup "7" will eventually be drop off after some idle period. Is there a way to generate the list of diskgroups consistently?

Answer 1

Hi,
If your database was configured manually (i.e not using DBCA) you should check v$(datafile,controlfile,logfile,block_change_tracking,etc) and parameters of database (log_archive_dest,db_recovery_file_dest,spfile,etc) to map these info.
If your database was configured using DBCA you can try it:
$ srvctl config database -d <database_name> |grep "Disk Groups"