Oracle Version : Oracle 9i on Solaris.

When I set the sql_trace with 'alter session set sql_trace=true', the trace file is generated in the bdump directory instead of udump directory.
The USER_DUMP_DEST parameter of the init.ora file is set to 'udump' and BACKGROUND_DUMP_DEST is set to bdump.

Why the trace file is generated in bdump ?

Thanks

Olivier Cante.