Compare two big tables in PL/SQL

I need to implement comparing 2 tables by set of keys (columns of compared tables). By this comparing i should check equal records (equal = equal by set of defined keys (columns in these input tables)) and then insert these records to report table with some calculated columns.

Also i need to get the different (by keys) records in these 2 tables and insert them to result table. This pl/sql stored procedure works correct, but completely unusable on real datasets (~ 30 million entries in each input table).

CREATE OR REPLACE procedure ASUPR_OUP."6.3.2" (
    upd_date in date
) 

as

-- filtered first input table
cursor c_end is select * from mon_end inner join dep on dep.dep = mon_end.depprod and dep.gpp_op = 1 and mon_end.division != 9 and mon_end.tehind not in (7,23) and (mon_end.depprod != mon_end.depcons or (mon_end.depprod = mon_end.depcons and dep.s_s = 1)) and mon_end.cyphdir in (1,7);

-- filtered second input table
cursor c_begin is select * from mon_begin inner join dep on dep.dep = mon_begin.depprod and dep.gpp_op = 1 and mon_begin.division != 9 and mon_begin.tehind not in (7,23) and (mon_begin.depprod != mon_begin.depcons or (mon_begin.depprod = mon_begin.depcons and dep.s_s = 1)) and mon_begin.cyphdir in (1,7);

is_found boolean;

begin

    for b_row in c_begin loop
        for e_row in c_end loop
            if (b_row.depprod = e_row.depprod) and (b_row.depcons = e_row.depcons) and
            (b_row.detail = e_row.detail) and (b_row.series = e_row.series) and (b_row.stk = e_row.stk) then
            begin
                if (b_row.trs != e_row.trs) or (b_row.trn != e_row.trn) or (b_row.kolsd != e_row.kolsd) or (b_row.applic != e_row.applic) then 
                begin
                    if e_row.s_s = 0 then 
                        begin
                            -- insert to result table          
                        end;    
                    else
                        begin                           
                            -- insert to result table 
                        end;
                    end if;
                end;
             end if;
            end;
            end if; 
        end loop;
    end loop;
    for b_row in c_begin loop
        is_found := false;
        for e_row in c_end loop
            if (b_row.depprod = e_row.depprod) and (b_row.depcons = e_row.depcons) and (b_row.detail = e_row.detail) 
            and (b_row.series = e_row.series) and (b_row.stk = e_row.stk) then
                begin
                    is_found := true;
                end;
            end if;
        end loop;
        if is_found = false
        then
            begin
                if b_row.s_s = 0 then
                    begin
                        -- insert to result table 
                    end;
                else
                    begin 
                       -- insert to result table 
                    end;    
                end if;
            end;
        end if;
    end loop;
    for e_row in c_end loop     
        is_found := false;
        for b_row in c_begin loop
            if (b_row.depprod = e_row.depprod) and (b_row.depcons = e_row.depcons) and (b_row.detail = e_row.detail) 
            and (b_row.series = e_row.series) and (b_row.stk = e_row.stk) then
                begin
                    is_found := true;
                end;
            end if;
        end loop;
        if is_found = false then        
            begin
                if e_row.s_s = 0 then
                    begin
                        -- insert to result table                 
                    end;
                else                    
                   begin              
                        -- insert to result table                             
                    end;                              
                end if;              
            end;
        end if;
    end loop;
end;

Can anyone suggest some way to boost performance of this procedure (i am using oracle 11g2) ? All input tables have indexes on used columns.