我有一个简单的下图：
http ://console.neo4j.org/?id=v0cvwn
我想知道为什么下面的查询：
START n=node(2)
match n-[:KNOWS]-node
return node.name as name
UNION
START n=node(2)
match n-[:ACTS_IN]-node
return node.name as name
抛出异常：
java.lang.AssertionError: assertion failed: Can't profile the same pipe twice
at scala.Predef$.assert(Predef.scala:179)
at org.neo4j.cypher.internal.profiler.Profiler.decorate(Profiler.scala:47)
at org.neo4j.cypher.internal.pipes.Pipe$class.createResults(Pipe.scala:35)
at org.neo4j.cypher.internal.pipes.NullPipe$.createResults(Pipe.scala:47)
at org.neo4j.cypher.internal.pipes.PipeWithSource.createResults(Pipe.scala:61)
at org.neo4j.cypher.internal.pipes.PipeWithSource.createResults(Pipe.scala:61)
at org.neo4j.cypher.internal.pipes.PipeWithSource.createResults(Pipe.scala:61)
at org.neo4j.cypher.internal.pipes.UnionIterator.loadNextIterator$1(UnionIterator.scala:60)
at org.neo4j.cypher.internal.pipes.UnionIterator.step$1(UnionIterator.scala:68)
at org.neo4j.cypher.internal.pipes.UnionIterator.stepIfNeccessary(UnionIterato
关于 UNION 的几个问题：
作为先前子查询中 UNION 的结果，是否可以对结果集中累积的所有数据执行另一个最终匹配子句？
是否可以根据该数据执行订单？
谢谢。