| From: | Mark Dilger <mark(dot)dilger(at)enterprisedb(dot)com> |
|---|---|
| To: | Tomas Vondra <tomas(dot)vondra(at)enterprisedb(dot)com> |
| Cc: | Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Use extended statistics to estimate (Var op Var) clauses |
| Date: | 2021-08-12 23:06:36 |
| Message-ID: | D78A3F4C-9A7B-42C8-8E6F-8D3E226488DE@enterprisedb.com |
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| Lists: | pgsql-hackers |
> On Aug 11, 2021, at 3:48 PM, Mark Dilger <mark(dot)dilger(at)enterprisedb(dot)com> wrote:
>
> I'm working on a correlated stats test as I write this. I'll get back to you when I have results.
Ok, the tests showed no statistically significant regressions. All tests included the same sorts of whereclause expressions as used in the tests from yesterday's email.
The first test created loosely correlated data and found no significant row estimate improvements or regressions.
The second test of more tightly correlated data showed a row estimate improvement overall, with no class of whereclause showing an estimate regression. I think the apparent regressions from yesterday were just statistical noise.
—
Mark Dilger
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
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