Sometimes we face issues on environment related to DB during database open with the messages as “unable to open undo tablespace” or with the below error messages.
ORA-01172: recovery of thread 1 stuck at block 1889 of file 3 ORA-01151: use media recovery to recover block, restore backup if needed
For such situation we can restore the corrupted temp tablespace or UNDO tablespace using recover command. The above error says that the datafile # 3 is corrupted and we should apply the below for restoring the file to its original state.
SQL> recover datafile 3; Media recovery complete. SQL> alter database open; Database altered.
In what situation such errors arrive?
When the database is not able to shutdown even though we issued a command “shutdown immediate”. The oracle processes are trying to shutdown but we trying to perform some operations in the database or changes to file systems.
You can check more on undo tablespace management here in Oracle site.