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Home -> Community -> Mailing Lists -> Oracle-L -> Re: db_file_mutliblock_read_count and physical IO
Ryan,
Was the data retrieved less than or equal to 8k? If it was than the
I/O should be the same as it will only retrieve the data that is needed
no matter what the db_file_multiblock_read_count(MBRC) is. Try the same
test making sure that the data you need it larger than the MBRC and
compare the results.
Just a thought.
Ron
>>> ryan.gaffuri_at_comcast.net 08/18/2004 10:25:17 AM >>>
I did a 10046 trace and verified that I can get up to 128 blocks/IO
with db_file_multiblock_read_count.
How do I metric this? I look at my total physical IOs when I did a
tkprof report and my total number of physical IOs remained the same when
I had the value set to 8 as when I had it set to 128?
Before I did this test, my assumption was:
'Oracle would do less total Physical IOs since I am retrieving more
blocks per IO.'
That assumption proved false. Can someone explain why?
-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html ----------------------------------------------------------------- ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Wed Aug 18 2004 - 10:22:21 CDT
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