Re: Use extended statistics to estimate (Var op Var) clauses - Mailing list pgsql-hackers

From Mark Dilger
Subject Re: Use extended statistics to estimate (Var op Var) clauses
Date
Msg-id 73847924-FC53-4FEF-8F0D-C4A94BC8E72D@enterprisedb.com
Whole thread Raw
In response to Re: Use extended statistics to estimate (Var op Var) clauses  (Tomas Vondra <tomas.vondra@enterprisedb.com>)
Responses Re: Use extended statistics to estimate (Var op Var) clauses  (Tomas Vondra <tomas.vondra@enterprisedb.com>)
Re: Use extended statistics to estimate (Var op Var) clauses  (Mark Dilger <mark.dilger@enterprisedb.com>)
List pgsql-hackers

> On Aug 11, 2021, at 3:45 PM, Tomas Vondra <tomas.vondra@enterprisedb.com> wrote:
>
> As I said in my last reply, I'm not sure it's particularly useful to look at overall results from data sets with
independentcolumns. That's not what extended statistics are for, and people should not create them in those cases ... 

We sent our last emails more or less simultaneously.  I'm not ignoring your email; I just hadn't seen it yet when I
sentmine. 

> Maybe it'd be better to focus on cases with the largest difference in estimates, and investigate those more closely.

Yeah, I'm working on a correlated stats test as I write this.  I'll get back to you when I have results.

—
Mark Dilger
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company






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