давай я тебе свой инишник кину. У меня размер базы примерно тот же. посмотри параметры, может что и пригодится. Я в свое время их тоже крутил, и себестоимость стала считаться раза в полтора быстрее (правда работаю на 8-ке)
processes = 150
shared_pool_size = 146800640
large_pool_size = 614400
java_pool_size = 32768
db_file_direct_io_count = 128
db_block_buffers = 60000
db_block_size = 8192
db_block_lru_latches = 2
db_writer_processes = 2
compatible = 8.1.6
log_buffer = 10485760
log_checkpoint_interval = 10000
log_checkpoint_timeout = 1800
db_files = 1024
db_file_multiblock_read_count = 64
max_rollback_segments = 99
rollback_segments = RBS0, RBS1, RBS2, RBS3, RBS4, RBS5, RBS6, RBS7, RBS8, RBS9, RBS10, RBS11, RBS12, RBS13, RBS14, RBS15, RBS16, RBS17, RBS18, RBS19, RBS20, RBS21, RBS22, RBS23, RBS24, RBS25, RBS26, RBS27, RBS28, RBS29, RBS30, RBS31, RBS32, RBS33, RBS34, RBS35, RBS36, RBS37
max_enabled_roles = 30
remote_login_passwordfile = EXCLUSIVE
global_names = TRUE
distributed_transactions = 10
instance_name = TEOREMA
service_names = TEOREMA
sort_area_size = 8192000
sort_area_retained_size = 4096000
db_name = TEOREMA
open_cursors = 100
job_queue_processes = 3
job_queue_interval = 60
parallel_max_servers = 5
hash_area_size = 16384000
background_dump_dest = f:\oracle\admin\TEOREMA\bdump
user_dump_dest = f:\oracle\admin\TEOREMA\udump
max_dump_file_size = 10240