[Info-ingres] stats on tables with more than 1million rows

[Martin Bowes]

Yes it's a single column unique primary key. So I would expect a count 1.

Marty

-----Original Message-----
From: Paul White [mailto:paul.white at shift7solutions.com.au] 
Sent: 28 January 2017 06:17
To: 'Ingres and related product discussion forum'
Subject: Re: [Info-ingres] stats on tables with more than 1million rows

Hi Marty and Karl,

If there is just a single column as unique primary key, the count needs to be 1, yes?

Paul

-----Original Message-----
From: info-ingres-bounces at lists.planetingres.org
[mailto:info-ingres-bounces at lists.planetingres.org] On Behalf Of Karl and Betty Schendel
Sent: Saturday, 28 January 2017 3:15 PM
To: Ingres and related product discussion forum
Subject: Re: [Info-ingres] stats on tables with more than 1million rows

Problem is, if you've sampled, you might have simply managed to get unique values.  I can easily imagine a table with values like 1, 1, 2, 2, 3, 3, 4, 4, getting only one of the two values when sampling, thus the sample would look unique but the true count per value is 2.

I don't know if there is a good answer, other than not sampling.

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