Incrementally Add New Records to Table

I have a table t_review that stores historical records including key sid and timestamp dt. Every day, more records come into table t_new. I use the following scripts to add those new records identified by sid in t_new to t_review.

begin
insert into t_review(sid, dt) select sid, sysdate from 
 (select sid from t_new minus select sid from t_review);
commit;
end;