Sim Zacks <sim@xxxxxxxxxxxxxx> writes: > Should there be any difference between: > select * from table1 a left join table2 b on a.pk=b.fk and b.typeid=14 > and > select * from table1 a left join table2 b on a.pk=b.fk > where coalesce(b.typeid,14)=14 Quite a lot: every A row is guaranteed to appear in the output of the first query, but not in the second. Consider for instance an A row that only joins to b row(s) having typeid 13. regards, tom lane
