V$ROLLNAME

V$ROLLNAME lists the names of all online rollback segments. It can only be accessed when the database is open.

Column Datatype NULL Description

Column	Datatype	NULL	Description
`USN`	`NUMBER`		Rollback (undo) segment number
`NAME`	`VARCHAR2(30)`	`NOT NULL`	Rollback segment name
`CON_ID`	`NUMBER`		The ID of the container to which the data pertains. Possible values include: `0`: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs. `1`: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data

USN

NUMBER

Rollback (undo) segment number

NAME

VARCHAR2(30)

NOT NULL

Rollback segment name

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.
1: This value is used for rows containing data that pertain to only the root
n: Where n is the applicable container ID for the rows containing data