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;

> test1_id | test2_id | test1_id
> ----------+----------+----------
> 1 | 1 | 1
> 2 | |

This is fixed for 7.3. If you need a fix now, the diff should work in
7.2 as well ... but I haven't tried it. See
http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/optimizer/util/relnode.c.diff?r1=1.39&r2=1.40&f=c

regards, tom lane