Question

我真的需要以下查询的帮助;对于CTE和连接，执行需要44秒以上，但是，当我运行单独的select语句时，每个只需要1秒。为什么加入它们需要44秒？

WITH Z
     AS (SELECT GM,
                YQ,
                IG
         FROM   FN_qryFYQI(@pYQ1)),
     Y
     AS (SELECT GM,
                YQ,
                IG
         FROM   FN_qryFYQI(@pYQ2))
SELECT Z.GM,
       Z.IG AS IG1,
       Y.IG AS IG2
FROM   Y
       INNER JOIN Z
         ON Y.GM = Z.GM

Answer 1

试试这个 -

SELECT  Z.GM
    ,   Z.IG AS IG1
    ,   Y.IG AS IG2
FROM FN_qryFYQI(@pYQ1) Y
JOIN (
    SELECT Z.GM, Z.IG
    FROM FN_qryFYQI(@pYQ2) Z
) Z ON Y.GM = Z.GM

优化连接的SQL CTE - Server 2008

1 个答案: