[COMMITTERS] pgsql: Avoid regressions in foreign-key-based selectivity estimates.

2017-06-19 Thread Tom Lane
Avoid regressions in foreign-key-based selectivity estimates. David Rowley found that the "use the smallest per-column selectivity" heuristic applied in some cases by get_foreign_key_join_selectivity() was badly off if the FK columns are independent, producing estimates much worse than we got befo

[COMMITTERS] pgsql: Avoid regressions in foreign-key-based selectivity estimates.

2017-06-19 Thread Tom Lane
Avoid regressions in foreign-key-based selectivity estimates. David Rowley found that the "use the smallest per-column selectivity" heuristic applied in some cases by get_foreign_key_join_selectivity() was badly off if the FK columns are independent, producing estimates much worse than we got befo