drop table t2 purge

drop table t1 purge

create table t1  
as 
select  *  
from    all_objects 
where   rownum <= 10000 

create table t2 
as 
select  * 
from    t1 
where   rownum <= 10 

create or replace procedure p1( myscn in varchar2 ) as 
  
        cursor c1 is 
                select  v1.object_name 
                from  
                        t1 as of scn myscn v1 
                join  
                        t2 as of scn myscn v2 
                on  
                        v2.object_id = v1.object_id 
        ; 
  
        l_row c1%rowtype; 
  
begin 
        open c1; 
        fetch c1 into l_row; 
        dbms_output.put_line(l_row.object_name); 
        close c1; 
end; 

create or replace procedure p1( myscn in varchar2 ) as 
  
        cursor c1 is 
                select  v1.object_name 
                from  
                        (select * from t1 as of scn myscn) v1 
                join  
                        (select * from t2 as of scn myscn) v2 
                on  
                        v2.object_id = v1.object_id 
        ; 
  
        l_row c1%rowtype; 
  
begin 
        open c1; 
        fetch c1 into l_row; 
        dbms_output.put_line(l_row.object_name); 
        close c1; 
end;