Class JoinPushExpressionsRule

  • public class JoinPushExpressionsRule
    extends RelOptRule
    Planner rule that pushes down expressions in "equal" join condition.

    For example, given "emp JOIN dept ON emp.deptno + 1 = dept.deptno", adds a project above "emp" that computes the expression "emp.deptno + 1". The resulting join condition is a simple combination of AND, equals, and input fields, plus the remaining non-equal conditions.