Re: Use extended statistics to estimate (Var op Var) clauses

On 8/12/21 12:48 AM, Mark Dilger wrote:
> 
> 
>> 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 independent columns.
>> 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 sent mine.
> 

Apologies, I didn't mean to imply you're ignoring my messages.

>> 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.
> 

Cool, thanks!


regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company