select dbms_flashback.get_system_change_number() from dual;
-- find where current SCN lives in SGA:
SQL> select ksmfsadr from x$ksmfsv where ksmfsnam = 'kcsgscn_';
KSMFSADR -------- 20009104
-- on 32bit environments this is the most significant half word of 8 byte SCN. To get the other, least significant half, you have to add 4 to the address and combine the results:
SQL> l
1 select dbms_flashback.get_system_change_number flashback_scn,
2 current_scn,
3 (select to_number(ksmmmval,'XXXXXXXX')
4 from x$ksmmem where addr = hextoraw('20009104')) * power(2,32) +
5 (select to_number(ksmmmval,'XXXXXXXX')
6 from x$ksmmem where addr = hextoraw('20009108')) direct_scn
7* from v$database
SQL> /FLASHBACK_SCN CURRENT_SCN DIRECT_SCN
------------- ----------- ----------
2633692 2633692 2633692The SCN lives in fixed part of SGA, thus its location doesn't change over instance bounces or SGA size changes. It might change only if you relink Oracle binary or change SGA mapped base address.
source:freelists.org
Regards
Manoj
