Oracle Undo Tablespace List by User - SQL

If you are a programmer and working with Oracle Database, you might be wondering how to get a list of undo tablespaces used by a particular user. This can be useful in troubleshooting performance issues, monitoring database growth, or simply checking on the usage of a particular user. In this article, we will discuss how to do this using SQL.

Steps to Get a List of Undo Tablespaces Used by a User

To get a list of undo tablespaces used by a particular user, you can use the following SQL query:

SELECT DISTINCT t.name
FROM v$transaction tr, v$session s, sys.ts$ t
WHERE tr.ses_addr = s.saddr
  AND t.ts# = s.ubafil + 1
  AND s.username = 'USERNAME';

In this query, replace USERNAME with the username of the user whose undo tablespaces you want to list.

How It Works

This SQL query works by joining three Oracle system views:

• v$transaction: This view contains information about active transactions in the database.
• v$session: This view contains information about current database sessions, including the user being used by each session.
• sys.ts$: This view contains information about the undo tablespaces in the database.

The DISTINCT keyword is used to remove duplicates from the result set.

The s.ubafil and t.ts# columns are used to match the session with the appropriate undo tablespace. The s.ubafil column contains the undo block file number used by the session, and the t.ts# column contains the undo tablespace number.

Conclusion

Getting a list of undo tablespaces used by a user in Oracle Database is a simple task that can be done using SQL. By understanding the system views used in this query, you can customize it to meet your specific needs.