eta.plan.expand_plan_node
- expand_plan_node(plan_node, subplan_node_start)[source]
Expand a plan node using the subplan headed by another node.
The subplan is inserted into the plan in place of the given plan node, which is done by adding the plan node as a superstep of each step in the subplan, and then modifying the pointers of the linked list so that the step before the plan node points to the first node in the subplan, and the step after the plan node points to the last node in the subplan.