Re: Columns correlation and adaptive query optimization

On 15.10.2019 1:20, legrand legrand wrote:
> Hello Konstantin,
>
> What you have proposed regarding join_selectivity and multicolumn statistics
> is a very good new !
>
> Regarding your auto_explain modification, maybe an "advisor" mode would also
> be helpfull (with auto_explain_add_statistics_threshold=-1 for exemple).
> This would allow to track which missing statistic should be tested (manually
> or in an other environment).
>
> In my point of view this advice should be an option of the EXPLAIN command,
> that should also permit
> auto_explain module to propose "learning" phase.
Thank you for good suggestion. Advisor mode is really good idea.
I have added "auto_explain.suggest_only" GUC.
When it is switched on, suggested CREATE STATISTICS statement is just 
printed in  log but not actually created.


-- 
Konstantin Knizhnik
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company