Re: Cross column statistics

From: Greg Stark <gsstark(at)mit(dot)edu>
To: Christopher Kings-Lynne <chriskl(at)familyhealth(dot)com(dot)au>
Cc: Greg Stark <gsstark(at)mit(dot)edu>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Cross column statistics
Date: 2005-02-08 17:51:25
Message-ID: 87u0oney8y.fsf@stark.xeocode.com
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Christopher Kings-Lynne <chriskl(at)familyhealth(dot)com(dot)au> writes:

> > B) gather a full matrix of the level of "correlation" between each column and
> > each other column. If this were a single floating point number per pair
> > then it might be feasible. It would still obviously be n^2 in the number of
> > columns though, so there would have to be some way to limit on how many
> > columns would be analyzed this way.
>
> Use foreign keys to just record those cross-correlations.

My email was about cross-column intra-table "correlations". inter-table
"correlations" are a whole other ball of wax.

--
greg

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