From: Justin Pryzby <pryzby@telsasoft.com>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: pgsql-hackers@postgresql.org
Subject: Re: PoC/WIP: Extended statistics on expressions
Date: Wed, 24 Mar 2021 12:18:16 -0500
Message-ID: <20210324171816.GC15100@telsasoft.com> (raw)
In-Reply-To: <CAEZATCXM0yC8i1x=hrkgqZVDQR6xjp2UYH7ZFHxY-G5nOb0ejw@mail.gmail.com>
References: <9f6654b1-ca31-f979-0fe8-137683818273@enterprisedb.com>
<20210324081402.GB28335@telsasoft.com>
<b8359875-b91f-ff48-4c6c-9b3c1c35d880@enterprisedb.com>
<20210324091708.GC28335@telsasoft.com>
<1ff3fc47-8f6e-7839-c3ff-6b694956f92e@enterprisedb.com>
<CAEZATCWYCY=2yEyxa6BwimCPQ_RZHy5GOb6U6i6dGHGQdjQESQ@mail.gmail.com>
<e4556e47-940d-58a6-73fd-16c5815dd2cd@enterprisedb.com>
<CAEZATCW2WHfsrbDLzwMvD+kOsBemLhvKwoHGhzR7STtac74XTg@mail.gmail.com>
<a7d17aec-234d-c7f2-bfdc-99c87767a507@enterprisedb.com>
<CAEZATCXM0yC8i1x=hrkgqZVDQR6xjp2UYH7ZFHxY-G5nOb0ejw@mail.gmail.com>
On Wed, Mar 24, 2021 at 05:15:46PM +0000, Dean Rasheed wrote:
> On Wed, 24 Mar 2021 at 16:48, Tomas Vondra
> <tomas.vondra@enterprisedb.com> wrote:
> >
> > As for the changes proposed in the create_statistics, do we really want
> > to use univariate / multivariate there? Yes, the terms are correct, but
> > I'm not sure how many people looking at CREATE STATISTICS will
> > understand them.
> >
>
> Hmm, I think "univariate" and "multivariate" are pretty ubiquitous,
> when used to describe statistics. You could use "single-column" and
> "multi-column", but then "column" isn't really right anymore, since it
> might be a column or an expression. I can't think of any other terms
> that fit.
We already use "multivariate", just not in create-statistics.sgml
doc/src/sgml/perform.sgml: <firstterm>multivariate statistics</firstterm>, which can capture
doc/src/sgml/perform.sgml: it's impractical to compute multivariate statistics automatically.
doc/src/sgml/planstats.sgml: <sect1 id="multivariate-statistics-examples">
doc/src/sgml/planstats.sgml: <secondary>multivariate</secondary>
doc/src/sgml/planstats.sgml: multivariate statistics on the two columns:
doc/src/sgml/planstats.sgml: <sect2 id="multivariate-ndistinct-counts">
doc/src/sgml/planstats.sgml: But without multivariate statistics, the estimate for the number of
doc/src/sgml/planstats.sgml: This section introduces multivariate variant of <acronym>MCV</acronym>
doc/src/sgml/ref/create_statistics.sgml: and <xref linkend="multivariate-statistics-examples"/>.
doc/src/sgml/release-13.sgml:2020-01-13 [eae056c19] Apply multiple multivariate MCV lists when possible
So I think the answer is for create-statistics to expose that word in a
user-facing way in its reference to multivariate-statistics-examples.
--
Justin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-hackers@postgresql.org
Cc: pryzby@telsasoft.com, dean.a.rasheed@gmail.com, tomas.vondra@enterprisedb.com
Subject: Re: PoC/WIP: Extended statistics on expressions
In-Reply-To: <20210324171816.GC15100@telsasoft.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox