Oracle ASM v$ Views Tips Oracle Tips by Burleson

Question:  What are the ASM v$ views?  I want to see my ASM diskgroups and I don't know which ASM view to search.  How many v$ASM views are there?

Answer:  Oracle has seven main v$ views to expose ASM details.  Oracle Automated Storage Management has several v$ views to see information About Automated Storage Management disks, diskgroups and other internals.

There are seven new v$ views provided in Oracle Database to monitor ASM structures.

v$asm_diskgroup:  Describes a disk group (number, name, size related info, state, and redundancy type) Contains one row for every open ASM disk in the DB instance.

v$asm_client:  Identifies databases using disk groups managed by the ASM instance. Contains no rows.

v$asm_disk:  Contains one row for every disk discovered by the ASM instance, including disks that are not part of any disk group. Contains rows only for disks in the disk groups in use by that DB instance.

v$asm_file:  Contains one row for every ASM file in every disk group mounted by the ASM instance. Contains rows only for files that are currently open in the DB instance.

v$asm_template:  Contains one row for every template present in every disk group mounted by the ASM instance. Contains no rows

v$asm_alias:  Contains one row for every alias present in every disk group mounted by the ASM instance. Contains no rows.

v$asm_operation:  Contains one row for every active ASM long running operation executing in the ASM instance. Contains no rows.

Oracle v$ views for ASM and their x$ tables

The v$ views for ASM  are built upon several ASM fixed tables, called x$ tables.  The x$ tables are not really tables, they are C language structures inside the SGA RAM heap:

X$ Table	v$ View
X$KFGRP	V$ASM_DISKGROUP
X$KFGRP_STAT	V$ASM_DISKGROUP_STAT
X$KFDSK	V$ASM_DISK
X$KFKID	V$ASM_DISK
X$KFDSK_STAT	V$ASM_DISK_STAT
X$KFKID	V$ASM_DISK_STAT
X$KFFIL	V$ASM_FILE
X$KFALS	V$ASM_ALIAS
X$KFTMTA	V$ASM_TEMPLATE
X$KFNCL	V$ASM_CLIENT
X$KFGMG	V$ASM_OPERATION
X$KFENV	V$ASM_ATTRIBUTE
X$KFNSDSKIOST	V$ASM_DISK_IOSTAT

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