Predicate Information (identified by operation id):
---------------------------------------------------

? 4 - filter("ENDSCN">12723393908514 AND "ENDSCN"<=12723394613470 AND ("STARTSCN" IS NULL OR
? ? ? ? ? ? ? "STARTSCN"<=12723393908514) AND ("OPERATION" IS NULL OR "OPERATION"<>'D'))
? 5 - filter("STARTSCN"<=12723393908514 OR "STARTSCN" IS NULL)
? 8 - filter("T"."VERSIONS_STARTSCN" IS NULL)
? 9 - access("RID"(+)=ROWIDTOCHAR("T".ROWID))
? ? ? filter("RID"(+)=ROWIDTOCHAR("T".ROWID))
? 10 - filter(("ENDSCN"(+) IS NULL OR "ENDSCN"(+)>12723394613470) AND ("STARTSCN"(+) IS NULL OR
? ? ? ? ? ? ? "STARTSCN"(+)<12723394613470))

3、如果SYS_FBA_还没有被创建，在flashback query的时候会到undo里获取(假设undo retention足够大，undo segment未被循环利用)
alter table t0517_1 no flashback archive;

drop table t0517_1;

create table t0517_1 (id number) tablespace TS0422_1 flashback archive fba0517_1;

insert into t0517_1 values(1);
insert into t0517_1 values(2);
insert into t0517_1 values(3);
commit;

select dbms_flashback.get_system_change_number from dual;
GET_SYSTEM_CHANGE_NUMBER
------------------------
? ? ? ? ? 12723378820886

delete from t0517_1 where id>=2;
commit;

update t0517_1 set id=11 where id=1;
commit;

col object_name format a20
set linesize 100
select object_name,created,object_id from dba_objects where object_name='T0517_1';
OBJECT_NAME? ? ? ? ? CREATED? ? ? ? ? ? ? ? ? OBJECT_ID
-------------------- ----------------- ----------------
T0517_1? ? ? ? ? ? ? 20150517 08:39:46? ? ? ? ? ? 37584

select owner,table_name,partitioned from dba_tables where table_name like '%37584';

no rows selected

explain plan for select * from t0517_1 as of scn 12723378820886;

SYS@tstdb1-SQL> set pagesize 100 linesize 150
SYS@tstdb1-SQL> select * from table(dbms_xplan.display);

PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 1027524507

-----------------------------------------------------------------------------
| Id? | Operation? ? ? ? | Name? ? | Rows? | Bytes | Cost (%CPU)| Time? ? |
-----------------------------------------------------------------------------
|? 0 | SELECT STATEMENT? |? ? ? ? |? ? 82 |? 1066 |? ? 2? (0)| 00:00:01 |
|? 1 |? TABLE ACCESS FULL| T0517_1 |? ? 82 |? 1066 |? ? 2? (0)| 00:00:01 |
-----------------------------------------------------------------------------