oradebug

On VMS, there is also orambx.

oradebug can be used to set a diagnostic event:

SQL> oradebug event <event_name> <action>

Event 10046 traces SQL statements. Hence, it's possible to initiate tracing sql statements of other sessions suing oradebug.

In order to do that, the Oracle process identifier must be found (column pid in v$process). For example, if it is 19, then the command is

oradebug setorapid 19

Now, tracing can be turned on:

oradebug event 10046 trace name context forever, level 12