Checking undo tablespace is a crucial aspect of Oracle database administration. It involves monitoring the size and usage of the undo tablespace, which stores the before-image of data modified by uncommitted transactions.
Maintaining an optimally sized undo tablespace is essential for ensuring database performance and preventing data loss. If the undo tablespace is too small, it can lead to ORA-01555 errors and transaction failures. On the other hand, an excessively large undo tablespace can consume excessive storage space and impact performance.