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. Regards PAscal -- Sent from: https://www.postgresql-archive.org/PostgreSQL-hackers-f1928748.html