ALERT LOG & OTHER TRACE FILES
- Alert log is the monitoring file which records following information useful for DBA in diagnosing the errors in the database
- All oracle related errors
- Every startup and shutdown timestamp
- Non-default parameters
- Archivelog generation information
- Checkpoint information (optional) etc.
- Alert log file will only specifies error message in brief, but it will point to a file which will have more information about the error. These are called trace files.
- Trace files are of 3 types – background trace files, core trace files and user trace files.
- If any background process fails to perform, it will throw error and a trace file will be generated (called background trace files) in ORACLE_HOME/admin/SID/bdump location.
- For all operating system related errors with oracle, trace files will be generated (called core trace files) in ORACLE_HOME/admin/SID/cdump location.
- For all user related errors, trace files (called user trace files) will be generated in ORACLE_HOME/admin/SID/udump location.
- The default location of these files can be changed by defining following parameters
Note: The above 3 parameters are replaced with a single parameter DIAG_DEST in oracle 11g.