Undo Tablespace has been corrupted with active rollback segment present in undo tablespace.
The database has been started using services.msc
But after logging into the database as sysdba privilege and issue of a command with dba_data_files and subsequent database status checking reveals that database has not been opened and is in mount state.
Shutdown immediate and startup from the command prompt throws the following error:
SQL> shutdown immediate;
ORA-01109: database not open
ORACLE instance shut down.
ORACLE instance started.
Total System Global Area 1071333376 bytes
Fixed Size 1375792 bytes
Variable Size 629146064 bytes
Database Buffers ...Read More