Information on all types of database problems can be found in the trace and ALERT files, where the actions in the database are recorded.
· In the ALERT file, important system events and significant error messages are continually collected for the entire system. The ALERT file can inform you, for example, which of the online redo log groups is the current one.
ALERT file: <SAPDATA_HOME>/saptrace/background/alert_<DBSID>.log
· Trace files are created by the individual background and user processes of the database system. Trace files thus offer more detailed information for error analysis than the ALERT file.
Trace files of the background processes: <SAPDATA_HOME>/saptrace/background/<process>_<number>.trc
Trace files of the user processes: <SAPDATA_HOME>/saptrace/usertrace/<process>.trc
The directories where the ALERT and trace files are stored are defined by the init.ora parameters background_dump_destination and user_dump_destination.
The naming conventions for the trace files depend on the operating system. Under UNIX, the name of the trace file contains the operating process number and the Oracle process number.
A trace file can contain the following information:
· Date and timestamp
· Version number
· Process information
· Error messages
· Calling stack trace
· Dumps from the System Global Area (SGA) and the Program Global Area (PGA).
For more information, see the Oracle documentation.