Re: two dimensional statistics in Postgres - Mailing list pgsql-hackers

From Tomas Vondra
Subject Re: two dimensional statistics in Postgres
Date
Msg-id 04ef58463197bcc46e78672c7a317bf1.squirrel@2.emaily.eu
Whole thread Raw
In response to Re: two dimensional statistics in Postgres  (Gavin Flower <GavinFlower@archidevsys.co.nz>)
List pgsql-hackers
Dne 6 Listopad 2014, 12:05, Gavin Flower napsal(a):
> On 06/11/14 23:57, Tomas Vondra wrote:
>> Dne 6 Listopad 2014, 11:50, Gavin Flower napsal(a):
>>> Could you store a 2 dimensional histogram in a one dimensional array:
>>> A[z] = value, where z = col * rowSize + row (zero starting index)?
>> How would that work for columns with different data types?
>>
>> Tomas
>>
> I implicitly assumed that all cells were the same size & type. However,
> I could devise a scheme to cope with columns of different types, given
> the relevant definitions - but this would obviously be more complicated.
>
> Also this method can be extended into higher dimensions.

Which is what I did in the "WIP: multivariate stats" ;-)

Tomas




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