@Override
public PlanNode visitLimit(LimitNode node, RewriteContext<Set<Symbol>> context) {
ImmutableSet.Builder<Symbol> expectedInputs =
ImmutableSet.<Symbol>builder().addAll(context.get());
PlanNode source = context.rewrite(node.getSource(), expectedInputs.build());
return new LimitNode(node.getId(), source, node.getCount());
}
@Override
public SubPlanBuilder visitLimit(LimitNode node, Void context) {
SubPlanBuilder current = node.getSource().accept(this, context);
current.setRoot(
new LimitNode(node.getId(), current.getRoot(), node.getCount(), node.getSampleWeight()));
if (current.isDistributed()) {
current.setRoot(
new SinkNode(
idAllocator.getNextId(), current.getRoot(), current.getRoot().getOutputSymbols()));
// create merge plan fragment
PlanNode source =
new ExchangeNode(
idAllocator.getNextId(), current.getId(), current.getRoot().getOutputSymbols());
LimitNode merge =
new LimitNode(idAllocator.getNextId(), source, node.getCount(), node.getSampleWeight());
current = createSingleNodePlan(merge).addChild(current.build());
}
return current;
}