Re: PCTFREE and PCTUSED

From: Pablo ksksksk <p_rodri99_at_yahoo.es>
Date: Wed, 20 Mar 2002 11:25:07 -0800
Message-ID: <F001.0042EE35.20020320112507@fatcity.com>

Thanks for the answer ANJO,

"Besides that pcfree/pctused will determine when blocks are put on the
freelist and when not. So probably what you want is multiple freelists to
take care of single freelist contention."

Let me ask you something about this.
The problem of having a small gap between PCTFREE/PCTUSED is that when a DML hits a block, there's a good chance that this block has to be moved in or out from one of the freelists.
This would generate contention on the HEADER BLOCK of the table (where ALL the freelists reside). So I think that by increasing the number of freelists I wouldn't be able to eliminate the contention (BBW waits) over the segment header.

Am I right about this?

I assume that there must be some DML on this table, I really cant tell as the audit is not on. How can I find out the concurrent number of updates in a table?
db_block_size=8K

thank you
Pablo

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Author: =?iso-8859-1?q?Pablo=20ksksksk?=   INET: p_rodri99_at_yahoo.es

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