Explain DBMS_APPLICATION_INFO for instrumenting long-running code

DBMS_APPLICATION_INFO.SET_MODULE(module, action) and SET_ACTION(action) stamp the current session's row in V$SESSION — invaluable for seeing what a batch job is doing right now, and for grouping in AWR/trace by module. SET_CLIENT_INFO adds a free-text field. SET_SESSION_LONGOPS drives the V$SESSION_LONGOPS progress bar for operations you can quantify. Set the module on entry, update the action per phase, and clear it on exit.

CREATE OR REPLACE PROCEDURE nightly_close AS
BEGIN
  DBMS_APPLICATION_INFO.SET_MODULE('NIGHTLY_CLOSE', 'start');

  DBMS_APPLICATION_INFO.SET_ACTION('validate');
  -- ... validation ...

  DBMS_APPLICATION_INFO.SET_ACTION('post_gl');
  -- ... posting ...

  DBMS_APPLICATION_INFO.SET_MODULE(NULL, NULL);   -- clear on exit
END;
/