Oracle flashback query syntax - all tables to same timestamp
Look at the DBMS_FLASHBACK package and the ENABLE_AT_TIME procedure (12.1 Documentation).  This allows you to do something like the following:

execute DBMS_FLASHBACK.Enable_At_Time(TIMESTAMP '2016-11-01 02:00:00');


The session will then run all queries as of the SCN most closely matching the provided timestamp.  

SELECT t1.Field1, t2.Field2
FROM table1 t1
JOIN table2 t2 ON t1.somekey = t2.somekey


To stop doing flashback queries as of the set timestamp, simply disable it.

execute DBMS_FLASHBACK.Disable;