查询需要更多时间在WHERE上

Question

MATCH (pr:PR)-[:CLOSED_ON]-(cls)  
WHERE  NOT(cls.closedDate = '' )  
RETURN pr

执行时间：588 ms

MATCH (pr:PR)-[:CLOSED_ON]-(cls)  
WHERE  NOT(cls.closedDate = '' ) 
AND apoc.date.parse(cls.closedDate,'s', 'MM/dd/yyyy') >= apoc.date.parse('01/01/2014','s', 'MM/dd/yyyy') 
AND apoc.date.parse(cls.closedDate,'s', 'MM/dd/yyyy') <= apoc.date.parse('06/13/2017','s', 'MM/dd/yyyy') 
RETURN pr

执行时间：2926 ms

pr节点数：35,000

为什么需要花更多时间在哪些声明上？