Re: multivariate statistics (v19) - Mailing list pgsql-hackers

From Michael Paquier
Subject Re: multivariate statistics (v19)
Date
Msg-id CAB7nPqStJ9rb7zTPrnNHDhM4qOkxM9ETzg4d=8zT6yiT_rv7vw@mail.gmail.com
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In response to Re: multivariate statistics (v19)  (Heikki Linnakangas <hlinnaka@iki.fi>)
Responses Re: multivariate statistics (v19)  (Dean Rasheed <dean.a.rasheed@gmail.com>)
List pgsql-hackers
On Mon, Oct 3, 2016 at 8:25 PM, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> Yeah. The idea was to use something like pg_node_tree to store all the
> different kinds of statistics, the histogram, the MCV, and the functional
> dependencies, in one datum. Or JSON, maybe. It sounds better than an opaque
> bytea blob, although I'd prefer something more relational. For the
> functional dependencies, I think we could get away with a simple float
> array, so let's do that in the first cut, and revisit this for the MCV and
> histogram later.

OK. A second thing was related to the use of schemas in the new system
catalogs. As mentioned in [1], those could be removed.
[1]: https://www.postgresql.org/message-id/CAB7nPqTU40Q5_NSgHVoMJfbyH1HDtqMbFDJ+kwFJSpam35b3Qg@mail.gmail.com.

> Separate columns for the functional dependencies, the MCVs,
> and the histogram, probably makes sense anyway.

Probably..
-- 
Michael



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