Simplified example query- explain select * from organizations o where id = id;
On a PG10 instance I get- Seq Scan on organizations o (cost=0.00..4.21 ***rows=1*** width=37) Filter: (id = id) On a PG11 instance with the same or very very similar data, I get- Seq Scan on organizations o (cost=0.00..5.70 ***rows=270*** width=37) Filter: (id IS NOT NULL) Given this is a not null field, it translates to "is true" basically. The real query that this example was extracted from apparently had a typo in the join resulting in this bogus id = id condition, but I still curious about where this estimate change comes from. *Michael Lewis | Database Engineer* *Entrata*
