if (viewPlan == null) {
viewPlan = planner.createPlan(context, view.getDefinition());
if (viewPlan != null) viewPlanCache.put(tableName, viewPlan);
}
if (viewPlan == null) continue; // there were likely errors when creating the plan
viewPlan = viewPlan.clone();
// Insert the view plan under the parent SOURCE node ...
sourceNode.addLastChild(viewPlan);
// Update the plan above this node to replace references to the view columns with references to the