and I get 'null' for the result.
SELECT dbms_transaction.local_transaction_id FROM dual
explain plan SET STATEMENT_ID = '1305182280989' for /**/ SELECT * FROM dual
As additional information (not sure if it is useful or not):
Error starting at line 1 in command: explain plan SET STATEMENT_ID = '1305182280989' for /**/ SELECT * FROM dual Error report: SQL Error: ORA-01031: insufficient privileges 01031. 00000 - "insufficient privileges" *Cause: An attempt was made to change the current username or password without the appropriate privilege. This error also occurs if attempting to install a database without the necessary operating system privileges. When Trusted Oracle is configure in DBMS MAC, this error may occur if the user was granted the necessary privilege at a higher label than the current login. *Action: Ask the database administrator to perform the operation or grant the required privileges. For Trusted Oracle users getting this error although granted the the appropriate privilege at a higher label, ask the database administrator to regrant the privilege at the appropriate label.