Oracle SQL*Loader does not support the sequence generation for direct loading.

Oracle SQL*Loader does not support the sequence generation for direct loading.
Under such case, the id could be added firstly on the file:
grep -n '^' file1.csv > file2.csv
sed "s/:/,/g" file2.csv > file3.csv
Then use direct load, should get the best performance.

Or use SEQUENCE(MAX,1)

If the direct load is false, then expression "seq_....nextval" could be used