Horton

Re: PoC/WIP: Extended statistics on expressions

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, pgsql-hackers@postgresql.org
Date: 2021-03-24T19:50:24Z
Lists: pgsql-hackers 
On 2021-Mar-24, Justin Pryzby wrote:

> On Wed, Mar 24, 2021 at 05:15:46PM +0000, Dean Rasheed wrote:

> > 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.

Agreed.  If we need to define the term, we can spend a sentence or two
in that.

> We already use "multivariate", just not in create-statistics.sgml

> 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.

+1

-- 
Álvaro Herrera       Valdivia, Chile

Commits

  1. Disallow extended statistics on system columns

  2. Identify simple column references in extended statistics

  3. Don't print extra parens around expressions in extended stats

  4. Change position of field "transformed" in struct CreateStatsStmt.

  5. Add transformed flag to nodes/*funcs.c for CREATE STATISTICS

  6. Stabilize stats_ext test with other collations

  7. Extended statistics on expressions

  8. Reduce duration of stats_ext regression tests

  9. Allow composite types in catalog bootstrap

  10. Convert Typ from array to list in bootstrap

  11. Disallow CREATE STATISTICS on system catalogs