Script" References MACLEAN‘s post Speed up the index creation.

alter session set workarea_size_policy=MANUAL;
alter session set db_file_multiblock_read_count=512;
alter session set events '10351 trace name context forever, level 128';
alter session set sort_area_size=734003200;
alter session set "_sort_multiblock_read_count"=128;
alter session enable parallel ddl;
alter session set db_file_multiblock_read_count=512;
alter session set db_file_multiblock_read_count=512;
alter session set "_sort_multiblock_read_count"=128;
alter session set "_sort_multiblock_read_count"=128;

spool create_index.log
@create_index.sql
spool offalter session set workarea_size_policy=MANU