System Trace Files | Oracle9i DBA JumpStart

An Oracle instance’s system trace files are stored in the same directory as the alert log file, in the directory specified by the system parameter BACKGROUND_ DUMP_DEST. The system trace files contain debugging, status, and error messages for each of the background processes, such as SMON, PMON, DBWx, LGWR, and so forth.

system trace file

A text file that pertains to a single background process and contains status, debugging, or error information about that background process. System trace files are stored in the directory specified by the system parameter BACKGROUND_DUMP_DEST.

Janice, the DBA, notices that there are quite a few system trace files in the BACKGROUND_DUMP_DEST directory:

D:\ORACLE\ADMIN\OR92\BDUMP> dir  Volume in drive D is DAT  Volume Serial Number is 2C2D-238A Directory of D:\ORACLE\ADMIN\OR92\BDUMP 11/16/2002  02:09 PM    <DIR>          . 11/16/2002  02:09 PM    <DIR>          .. 11/16/2002  02:14 PM        5,378 alert_or92.log 11/15/2002  03:16 AM       27,239 alert_or92_2002-11-15.log 11/15/2002  03:15 AM          947 or92_arc0_2172.trc 11/16/2002  09:36 AM        1,011 or92_arc1_1420.trc 11/07/2002  09:05 PM          597 or92_lgwr_2084.trc 11/07/2002  08:58 PM          597 or92_lgwr_2944.trc 11/07/2002  09:10 PM          597 or92_lgwr_3280.trc 11/07/2002  08:49 PM          597 or92_lgwr_3636.trc 11/16/2002  02:09 PM          597 or92_lgwr_3856.trc                9 File(s)         37,560 bytes                2 Dir(s)  40,448,815,616 bytes free D:\ORACLE\ADMIN\OR92\BDUMP>

She sees quite a few files for the LGWR (log writer) background process, so she is concerned that there might be a problem with LGWR. She opens the most recent LGWR trace file, or92_lgwr_3856.trc, to see what the problem might be.

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She looks at the date stamp and realizes that the time the LGWR process was shutting down was the same time that the database was restarted that day:

select instance_name,    to_char(startup_time,’yyyy-mm-dd hh:miPM’)    from v$instance; INSTANCE_NAME    TO_CHAR(STARTUP_TI ---------------- ------------------ or92             2002-11-16 02:13PM 1 row selected.

As a result, the trace file is merely informational in this case, and there appears to be nothing wrong with the LGWR.