Horton

Re: PoC/WIP: Extended statistics on expressions

Dean Rasheed <dean.a.rasheed@gmail.com>

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From: Dean Rasheed <dean.a.rasheed@gmail.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Justin Pryzby <pryzby@telsasoft.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2021-03-24T17:15:46Z
Lists: pgsql-hackers 
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.

Regards,
Dean

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