Re: Improving our clauseless-join heuristics

Amit Kapila <amit.kapila@huawei.com> writes:
> The way I am telling was as below code. 
> With this extra paths will get generated, but it will as well consider for
> joining c and d in query:
> select * from a, b, c, d where a.x = b.y and (a.z = c.c or a.z = d.d)

I think this would just be dead code as of HEAD.  With the recent
changes in the definition of have_relevant_joinclause, if we get into
make_rels_by_clause_joins there should always be at least one other
relation that the old_rel is considered to join to.  In any case,
I don't see the point of adding more logic to make_rels_by_clause_joins
unless it allows us to take out as much or more work elsewhere.
        regards, tom lane