René Nyffenegger's collection of things on the web
René Nyffenegger on Oracle - Most wanted - Feedback -

Trace files in Oracle

When one of the Oracle background processes (such as dbwr, lgwr, pmon, smon and so on ) encounter an exception, they will write a trace file.
These trace files are also recorded in the alert.log.
Trace files are also created for diagnostic dump events.
An ORA-00600 error also produces a trace file.

Format of a trace file

See this link: trace files

Public readability of trace files

By default, trace files are only readable by the Oracle OS user (on Unix, that is, I don't know how this behaves on Windows). This setting can be altered with _trace_files_public.

Name and location of the trace file

Note: the name of the trace file can be changed (to make it easier to find it) with
alter session set tracefile_identifier = 'some_id';

Maximum size for a trace file

The maximum size for trace files can be specified with max_dump_file_size.