Re: two dimensional statistics in Postgres

Hi,

2014-11-06 9:57 GMT+01:00 Katharina Büchse <katharina(dot)buechse(at)uni-jena(dot)de>:

> Thank you for your help! I'll try in pgsql-hackers then :-)
>
>
Good :)

>
> On 05.11.2014 18:22, Guillaume Lelarge wrote:
>
> Hi,
>
> I'm not sure why you thought a mailing list on an admin tool would be a
> better fit,
>
> if nothing fits, you just choose anything ;-) My first try was even
> someone from the German mailing list (that's why the subject of the mail
> was still German, sorry for that), but after some mail exchange he just
> suggested to write to a developer mailing list. So I read all the
> descriptions of the mailing lists and it was like "no -- no -- no --- ...."
>
>
I understand the feeling :) It's not easy to choose the good one.

> but it definitely is not. Don't worry, this isn't a big issue :-)
>
> Anyway, pgsql-hackers is the list you're looking for.
>
> On the patch you'd like to work on, I'd advise you someone else is working
> on this. You should read the "WIP: multivariate statistics / proof of
> concept" thread on the hackers list. I'm pretty sure you could get some
> help from Tomas.
>
> Patches on this topic are of high interest. If I can be of any help, let
> me know.
>
> Regards.
> Le 5 nov. 2014 18:03, "Katharina Büchse" <katharina(dot)buechse(at)uni-jena(dot)de>
> a écrit :
>
>> Hi,
>>
>> I was unsure to which mailing list to write, in my opinion psql-hackers
>> would fit best, but as it is not recommended to write there directly, I'm
>> trying here.
>> I'm a phd-student at the university of Jena, Thüringen, Germany, in the
>> field of data bases, more accurate query optimization.
>> I want to implement a system in PostgreSQL that detects column
>> correlations and creates statistical data about correlated columns for the
>> optimizer. Therefore I need to store two dimensional statistics (especially
>> two dimensional histograms) in PostgreSQL. I would like to know where I
>> have to "touch" the source code and make changes, so that the PostgreSQL
>> optimizer will also take into consideration my statistical data? I also
>> need a possibility to extract data from query results (tuple counts and,
>> speaking a little inaccurately, the where-part of the query itself). Of
>> course I tried to have a look at the PostgreSQL source code, but it's
>> impossible to understand everything within a few weeks or even months....
>>
>> I'd be grateful for any advices.
>> Regards,
>>
>> Katharina
>>
>> --
>> Dipl.-Math. Katharina Büchse
>> Friedrich-Schiller-Universität Jena
>> Institut für Informatik
>> Lehrstuhl für Datenbanken und Informationssysteme
>> Ernst-Abbe-Platz 2
>> 07743 Jena
>> Telefon 03641/946367
>> Webseite http://users.minet.uni-jena.de/~re89qen/
>>
>>
>>
>> --
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>>
>
>

--
Guillaume.
http://blog.guillaume.lelarge.info
http://www.dalibo.com