Database Software

Hello,
the 11gR2 manual says something like this about output of queries against this view:
SELECT * FROM V$STANDBY_EVENT_HISTOGRAM WHERE NAME = 'apply lag'
AND COUNT > 0;

NAME TIME UNIT COUNT LAST_TIME_UPDATED
--------- --------- -------- ----------- ------------------------
apply lag 0 seconds 79681 06/18/2009 10:05:00
apply lag 1 seconds 1006 06/18/2009 10:03:56
apply lag 2 seconds 96 06/18/2009 09:51:06
apply lag 3 seconds 4 06/18/2009 04:12:32
apply lag 4 seconds 1 06/17/2009 11:43:51
apply lag 5 seconds 1 06/17/2009 11:43:52

Now on a Linux with 11.2.0.2 where I have physical standby in place and with managed recovery in place (no log gap), I get this:

SELECT name, value, datum_time, time_computed FROM V$DATAGUARD_STATS
2 WHERE name like 'apply lag';

NAME VALUE
-------------------------------- --------------------
DATUM_TIME TIME_COMPUTED
------------------------------ ------------------------------
apply lag +00 00:06:20
01/17/2011 11:59:55 01/17/2011 11:59:55

But a query on the view in subject gives no rows....
SELECT * FROM V$STANDBY_EVENT_HISTOGRAM WHERE NAME = 'apply lag'
AND COUNT > 0;

no rows selected

SQL> select count(*) from V$STANDBY_EVENT_HISTOGRAM;

COUNT(*)
----------
0

Any reason for this? Anythging to enable to get it populated?

Thanks,
Gianluca