Supporting join pushdown for outer joins

For a query that contains an OUTER join, you can add the inner table rows to its outer table rows while implementing the join pushdown processing.

For example, consider the following query:

Select * from emp left outer join dept inner join salary where emp.id = dept.empid and emp.id = salary.empid;

When IPEXECUTE is called for the outer table (emp), you can add inner table (dept) rows to its outer table (emp). Also, you can add inner table (salary) rows to its outer table (dept).