Re: stats not playing nice

From: Stefan Koehler <>
Date: Mon, 27 Feb 2017 04:12:09 +0100 (CET)
Message-ID: <>

Hey Jack,
this paper by Alberto Dell'Era answers your question:  

Best Regards
Stefan Koehler

Independent Oracle performance consultant and researcher Website:
Twitter: _at_OracleSK
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> Jack van Zanen <> hat am 27. Februar 2017 um 03:08 geschrieben:
> Hi All,
> Oracle 11G R2 AIX
> We have a fairly large table (24G) that has a status field.
> there are 6 possible statuses and the Majority are status 5(completed) for which there is a need to retain for 13 months.
> Now the stats on that table take fairly long to compute so estimate is used, but as the data is very skewed sometimes we miss out on some values
> altogether.
> Now, I think the best solution would have been at creation time to split this up and move the completed records to a separate table partitioned by
> month and keep the batch processing to use the lean and mean table.
> Failing that:
> I can:
> a) Run a full compute statistic at an opportune time including histograms (takes a long time and I am not sure we get a window for this. and than
> lock the stats untill we do it again
> b) keep using estimate statistics and manually insert the values for this one column.
> I have found a blog post on Jonathan Lewis website where he has an example that is fairly easy to follow:
> This is the Code from Jonathan Lewis blog post from almost a decade ago.
> I have one question regarding the density. What should I be putting here

Received on Mon Feb 27 2017 - 04:12:09 CET

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