Thoughts on Parallelization

  • From: "Don Seiler" <don@xxxxxxxxx>
  • To: oracle-l <oracle-l@xxxxxxxxxxxxx>
  • Date: Tue, 15 May 2007 15:48:13 -0500

I've been doing some reading on parallelization, after seeing Doug
Burns' presentation on the Pythian blog a while back.  In it, Doug
mentioned that he doesn't set any degree of parallelization on tables
or indexes, and relies on query hints to use parallel query.

I'm wondering what others might think of this, or if relying on
Oracle's multi-user adaptive logic to control things is fine.  I
realize that there might be some extreme cases, but I'm wondering if
you people are happily using the default parallelism on your tables
and indexes and living life to the fullest.

Also, what about the equation for setting parallel_max_servers.  The
documentation suggests:

otherwise 1) x 5

My CPU_COUNT is 8, but that is due to linux hyperthreading on 4
physical CPUs.  So even then I'm looking at 4 x 2 x 2 x 5 = 80
paralllel_max_servers.  (Running on RHEL3).  I'm not sure
what to expect so I'd like to see what others are using in their
setups, if you're willing to share.

Don Seiler
oracle blog:

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