用連接返回具有特定值的行

Question

我有一個相當複雜的連接查詢，我想從中選擇圍繞具有某個ID的結果的幾行。

查詢目前看起來是這樣的：

WITH results AS 
    (
    SELECT t1.id, t1.position, t1.points, t2.name 
     ROW_NUMBER() OVER(ORDER BY t1.position ASC, t1.points DESC) AS rn 
     FROM Table1 t1 
     JOIN Table2 t2 ON t1.id = t2.Table1id 
     /* Several more joins here, some of which limit the result set */ 
) 
SELECT * FROM results 
WHERE rn < (SELECT rn+3 FROM results WHERE id = @someid) 
AND rn > (SELECT rn-3 FROM results WHERE id = @someid) 

有沒有更好的辦法來解決這個問題？最重要的是，我擔心這些多次呼叫可能會導致巨大的CTE表現。

該查詢在SQL 2008服務器上運行。

Answer 1

也許從CTE拉出連接。
這樣查詢優化器有機會在處理連接之前過濾出行。

WITH results AS 
    (
    SELECT t1.id, t1.position, t1.points 
     , ROW_NUMBER() OVER(ORDER BY t1.position ASC, t1.points DESC) AS rn 
     FROM Table1 t1  
) 
SELECT results.id, results.position, results.points, t2.name 
FROM results 
JOIN Table2 t2 ON t2.id = results.Table1id 
     /* Several more joins here */ 
WHERE rn < (SELECT rn+3 FROM results WHERE id = @someid) 
    AND rn > (SELECT rn-3 FROM results WHERE id = @someid)