Re: How does postgres store the join predicate for a relation in a given query

A Join clause/predicate will only mention 2 relations. It can't have 3 or
more relations.

On 12 October 2017 at 23:14, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Gourav Kumar <gourav1905(at)gmail(dot)com> writes:
> > My objective is to construct join graph from a given query.
> > A join graph, has a node for each relation involved in a join, and an
> edge
> > between two relations if they share a join predicate among them.
>
> Hm, well, you could adapt the logic in have_relevant_joinclause() and
> have_relevant_eclass_joinclause(). Or maybe you could just use them
> as-is ... depends on what you have in mind to do with join clauses
> that mention 3 or more relations.
>
> regards, tom lane
>

--
Thanks,
Gourav Kumar
Computer Science and Automation
Indian Institute of Science