Re: Bug #795: null resulting from left join corrupts select

pgsql-bugs(at)postgresql(dot)org writes:
> select
> *
> from
> test1 left join test2 on (test1.test1_id = test2.test1_id)
> where
> test1.test1_id = test2.test1_id;

Hm. I think what is happening is that the planner is (mistakenly)
deciding that the where-clause and on-clause are equivalent, and
so dropping the second one ...

regards, tom lane