RE: best way to invoke parallel in DW loads?

From: Amihay Gonen <Amihay.Gonen_at_ecitele.com>
Date: Wed, 16 Sep 2009 16:54:00 +0300
Message-ID: <5BB479729855824B9A8B9724F455F70E01035FC73AD1_at_ILPTMAIL02.ecitele.com>



In 11Gr2 this parameter can be used to CPU caging.

-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Martin Berger Sent: Wednesday, September 16, 2009 4:47 PM To: Dave.Herring_at_acxiom.com
Cc: nkodner_at_gmail.com; oracle-l_at_freelists.org Subject: Re: best way to invoke parallel in DW loads?

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

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Received on Wed Sep 16 2009 - 08:54:00 CDT

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