Trace Files
A trace file is created each time an
Oracle instance starts or an unexpected event occurs in a user process or
background process. The name of the trace file includes the instance name, the
process name, and the Oracle process number. The file Extension or file type is
usually TRC, and, if different, is noted in your operating System-specific
Oracle documentation. The contents of the trace file may include dumps of the
system global area, process global area, supervisor stack, and registers.
Two initialization parameters are used to specify the
location of the trace files.
The BACKGROUND_DUMP_DEST specifies the location of
trace files created by the Oracle background processes PMON, DBWR, LGWR and
SMON.
The USER_DUMP_DEST specifies
the location of trace files created by user processes such as SQL*Loader or
Pro*C.
Major error shows in trace file is :
*** 2002.10.23.09.20.38.190
*** SESSION ID:(18.1395)
2002.10.23.09.20.34.104
FATAL ERROR IN TWO-TASK SERVER:
error = 12571
*** 2002.10.23.09.20.38.250
ksedmp: internal or fatal error
The Alert file also describes the
location of trace files generated when internal errors occur. You may need to
format the trace file before using it to diagnose problems. To format a trace
file, use the DUMPFMT utility, which is available on most systems and is
described in your operating system-specific Oracle documentation. Oracle
Support Services may ask you for a formatted trace file to help solve a problem.
The Alert File
The Alert file is a log file that
records information about internal errors and administrative activities, such
as backups. When an internal error occurs, the message is sent to the terminal
screen as well as written to the Alert file.
Oracle also writes additional information about internal
errors to the Alert file, such as the location and name of any trace files
generated because of the error. The name of the Alert file is operating
system-specific. The location of the Alert file is the same as the location of
the background process trace files. This location is specified by the
BACKGROUND_DUMP_DEST.
The Alert file also records information about administrative
activities, such as backups and archiving online redo log files.
Monitoring Errors with Trace Files
and the Alert Log
Each server and background process
can write to an associated trace file. When an
internal error is detected by a process, it dumps information about the error
to its trace file. Some of the information written to a trace file is intended
for the database administrator, and other information is for Oracle Support
Services. Trace file information is also used to tune applications and
instances.
Alert.log is a text file that can be opened with any text
editor. The location can be determined by:
SQL>Select value from v$parameter
where name = 'background_dump_dest';
If the background_dump_dest parameter is not specified,
Oracle will write the alert.log into the $ORACLE_HOME/RDBMS/trace
directory.
Common messages in the Alert log
ARCx: Media recovery disabled
This message will be written into
the Alert. Log if the arch process is started with the database being in
noarchive log mode.
Thread 1 cannot allocate new log,
sequence 1558 Checkpoint not complete
This error message is written into
the alert.log if a checkpoint cannot write all dirty db blocks to the online
redo log. Usually, this message is a sign that the size of the redo logs is
too small or that there should be more of them.
All internal Errors: ORA-00600,
Block Corruption Errors: ORA-01578 and deadlock errors ORA-00060
that occur recorded in alert Log file.
Administrative operations, such
as CREATE, ALTER, and DROP statements and STARTUP, SHUTDOWN,
and ARCHIVELOG statements are recorded in alert Log file.
Messages and Errors relating to the
functions of shared server and dispatcher processes
Errors occurring during the automatic
refresh of a Materialized view
The values of all initialization
parameters that had nondefault values at the time the database and
instance start
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