database A

create table..a_stg

procedure procA is
begin
     execute immediate..truncate a_stg;

     insert into a_stg
     select sum()...etc.;
end;

We ran first this procA here in database A

Then in...

database B

procedure procB is
begin
     insert into b_table
     select ... from a_stg@databaseA;
end;

Run procB.

Session 1:

create table t_at_db1(x int);

insert into t_at_db1 values(2);


Session 2:

create table t_at_db2(x int);
insert into t_at_db2 values(5);

create procedure p is
begin
    execute immediate 'truncate table t_at_db2';
end;
/

Session 1:

SQL> begin
  2      update t_at_db1 set x = 4;
  3      execute immediate 'truncate table t_at_db2@link';
  4      --p@link;
  5  end;
  6  /
begin
*
ERROR at line 1:
ORA-02021: DDL operations are not allowed on a remote database
ORA-06512: at line 3

Using procedure

SQL> begin
  2      update t_at_db1 set x = 4;
  3      --execute immediate 'truncate table t_at_db2@link';
  4      p@link;
  5  end;
  6  /

PL/SQL procedure successfully completed.