What is the INSTANCES modifier of the PARALLEL clause?

  • From: "Rich Jesse" <rjoralist@xxxxxxxxxxxxxxxxxxxxx>
  • To: oracle-l@xxxxxxxxxxxxx
  • Date: Mon, 31 Mar 2008 11:03:54 -0500 (CDT)

Hey all,

I'm looking to implement parallelism for our largest tables in on
AIX in order to more fully utilize our SAN.  While continuing testing with
various parameters, I've been seeing that there is an INSTANCES qualifier of
the PARALLEL clause in the ALTER TABLE statement.

>From experiment, it appears to affect whether or not parallelism is used for
certain queries (I think there was just a thread here about that, but
regarding the DEGREE qualifier).  The kicker is that I can't find any
documentation on INSTANCES.

Docs on tahiti.oracle.com do not mention it in the 10.1, 10.2, or even the
11.1 version for the ALTER TABLE command, and a search for "parallel
instances" is nearly futile with the number of unrelated hits on

Anyone have any pointers on this?  Thanks!


Other related posts: