if you deleted/updated data by mistake in oracle. and try to recover data from flashback query. Your query may fail with ora-01555 error:
SQL> l 1 declare 2 cursor c is select * from testt2 as of scn 5385449; 3 begin 4 for i in c loop 5 null; 6 end loop; 7* end;SQL> /declare*ERROR at line 1:ORA-01555: snapshot too old: rollback segment number with name "" too smallORA-06512: at line 4
if you have no backup , then you can not recover data in this case .
we provide a better flashback service , it can recover part of deleted data . for example .
SQL> set serveroutput on;
SQL> exec better_flashback_table_save('TEST2','TESTT2',2843925,'MYTVSAVE3');
table TEST2.TESTT2 @ scn 2843925 find 5568 rows , copied to TEST2.MYTVSAVE3
PL/SQL procedure successfully completed.
the service step :
1. first expand your undo_retention parameter :
alter system set undo_retention=86400;
expand all undo datafiles
alter database datafile 'undofile' resize BIGGER_SIZE;
the first step avoid undo extent reused by system
2. we will provide procedure better_flashback_table_query , check how many rows can be recovered
3. we will provide procedure better_flashback_table_save , which will recover data and stored in new table .
4. we can also take advantage prm-dul undelete function to help you recover data . pls check https://youtu.be/hIYutqNcVBI
We provide above as a service . contact service@parnassusdata.com