Re: best way to invoke parallel in DW loads?
Date: Wed, 16 Sep 2009 15:46:51 +0200
Message-ID: <cd8f74560909160646s73f63bd0jafb06b6adfbdf7df_at_mail.gmail.com>
Dave,
just a small correction:
(at least in 11.1.0.7, have not tested 10gR2) these parameters are
calculated from CPU_COUNT:
__db_cache_size
__shared_pool_size
_cursor_db_buffers_pinned
_db_block_buffers
_db_block_lru_latches
_enqueue_hash_chain_latches
_enqueue_locks
_flashback_generation_buffer_size
_kghdsidx_count
_log_parallelism_max
_log_simultaneous_copies
_num_longop_child_latches
_parallel_min_message_pool
_shared_server_num_queues
_small_table_threshold
_spin_count
_sqlmon_max_plan
cpu_count
db_writer_processes
log_buffer
parallel_max_servers
> CPU_COUNT -> please don't change this. Let Oracle figure it out. In 10g it's an underscore parameter and it doesn't make much sense to mess with it. The only impact that a manual change will have (I believe) is the default parallel degree, calculated by CPU_COUNT * PARALLEL_THREADS_PER_CPU.
Neil, if you want to tweek there, be careful and make good records about all related changes for tracability.
hth
Martin
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Sep 16 2009 - 08:46:51 CDT