| -- Shape: IN correlated on `<` instead of `=`. The `IN` equality is the hash key | |
| -- and the `<` correlation stays a residual filter of the one null-aware mark | |
| -- join, which applies it when it decides whether a NULL makes the mark UNKNOWN. | |
| SELECT | |
| count(*) FILTER (WHERE m) AS true_count, | |
| count(*) FILTER (WHERE m IS NULL) AS null_count | |
| FROM (SELECT id, id IN (SELECT i.id FROM inner_t i WHERE i.z < o.z) AS m FROM outer_t o); |