Re: Preventing delayed block cleanout due to loading a datawarehouse

From: Donatello Settembrino <>
Date: Thu, 21 Apr 2011 02:54:05 -0700 (PDT)
Message-ID: <>

On 20 Apr, 11:37, Randolf Geist <> wrote:
> On Apr 19, 2:51 pm, Donatello Settembrino
> <> wrote:
> > Exactly, that's right
> By the way - we digress - my comment about PCTFREE is irrelevant in
> this case since Oracle will stuff this row into a single block no
> matter what the PCTFREE setting is as long as the row fits into the
> block.
> And: You don't have chained rows but your test case is flawed: A
> select count(*) never reports "table fetch continued row" because it
> does not have to visit the columns but only accesses the row entries
> in the row directory. So even with chained rows your test will not
> report any "table fetch continued row" statistics. You would need to
> count/access a column that is part of the "chained" row pieces - and
> it would have to be nullable, otherwise recent versions of Oracle will
> transform a count(col) to a count(*).
> Randolf

Thanks for the correction,
when I did the second time the test
I forgot to change the query
(select count (col) from table) then,
the test may be incorrect
for the reasons you highlighted.

Donatello Received on Thu Apr 21 2011 - 04:54:05 CDT

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