Insert with a select, Insert with a select Options

[avdba_22]

We are using 10g. I have to load about 15million records or more from staging table into another table. It is a OLTP environment. And it is taking about 1 hrs to do this.

I am doing :

insert into t_so(SO_ID,
FIRST_NAME,
LAST_NAME,
ADDRESS1,
ADDRESS2,
MIDDLE_INITIAL,
CITY_STATE_ZIP_ID)
SELECT seq_So.nextval,
PCFIRST,
PCLAST,
substr(PCMINIT, 1,1) PCMINIT,
PCPADDR,
PCSADDR,
pkg_so.fn_get_city_state_zip_id ( PCCITY , PCSTATE, PCZIP5)
FROM t_stage;

I optimized the function and there is lot of improvement . Could any of you suggest anything more I could do to improve performance in 10g. Please let me know .

Thanks