CopyManager(In/out) vs. delete/insert directly

Hello,

Two options for data (>1M), may I know which one better please?

(1) copyOut (JDBC copyManager)
t1 into a.csv
delete t2 where pk.cols in t1
copyIn t2 from a.csv

(2) setautoCommit(false);
delete t2 where pk.cols in t1;
insert t2 select * from t1;

Thank you
Emi