When you try to open your database, you receive the following error:
ORA-00205: error in identifying controlfile
Where would you find the details required to resolve this error?
A. audit trail
B. alert log file
C. user trace file
D. online trace file
E. background trace file
F. operating system event viewer
Answer: B
ORA-00205: error in identifying control file, check alert log for more info
Cause: The system could not find a control file of the specified name and size.
Action: Check that ALL control files are online and that they are the same files that the system created at cold start time.
Alert Log
Each database has an alert log, which is an XML file containing a chronological log of database messages and errors. The alert log contents include the following:
All internal errors (ORA-600), block corruption errors (ORA-1578), and deadlock errors (ORA-60)
Administrative operations such as DDL statements and the SQL*Plus commands STARTUP, SHUTDOWN, ARCHIVE LOG, and RECOVER
Several messages and errors relating to the functions of shared server and dispatcher processes
Errors during the automatic refresh of a materialized view
Oracle Database uses the alert log as an alternative to displaying information in the Enterprise Manager GUI. If an administrative operation is successful, then Oracle Database writes a message to the alert log as "completed" along with a time stamp.
Oracle Database creates an alert log in the alert subdirectory when you first start a database instance, even if no database has been created yet.
alert是最先创建来记录问题的，开机出现问题一般都会记录。
SQL> select * from alert where upper(log) like '%CONTROL%'; LOG -------------------------------------------------------------------------------- control_files = "/home/oracle/app/oracle/oradata/orcl/control01.ctl control_files = "/home/oracle/app/oracle/flash_recovery_area/orcl/c Create controlfile reuse set database "orcl" Completed: Create controlfile reuse set database "orcl" control_files = "/home/oracle/app/oracle/oradata/orcl/control01.ctl control_files = "/home/oracle/app/oracle/flash_recovery_area/orcl/c Create controlfile reuse set database "orcl" Completed: Create controlfile reuse set database "orcl" but not in the controlfile. Adding to controlfile. This condition can occur when a backup controlfile has 1. A backup controlfile was restored. 2. A standby controlfile was restored. 3. The controlfile was re-created. LOGSTDBY: Validating controlfile with logical metadata control_files = "/home/oracle/app/oracle/oradata/orcl/control01.ctl control_files = "/home/oracle/app/oracle/flash_recovery_area/orcl/c Updating character set in controlfile to WE8MSWIN1252 control_files = "/home/oracle/app/oracle/oradata/orcl/control01.ctl control_files = "/home/oracle/app/oracle/flash_recovery_area/orcl/c control_files = "/home/oracle/app/oracle/oradata/orcl/control01.ctl LOG -------------------------------------------------------------------------------- control_files = "/home/oracle/app/oracle/flash_recovery_area/orcl/c