The database users regularly complain about the difficulty in performing transactions. On investigation, you find that some users perform long-running transactions that consume huge amounts of space…

The database users regularly complain about the difficulty in performing transactions. On investigation, you find that some users perform long-running transactions that consume huge amounts of space in the undo tablespace, which caused the problem. You want to control the usage of the undo tablespace only for these user sessions and you do not want these sessions to perform long-running operations. How would you achieve this?