Sql Server聯合查詢優化

Question

我已經給出了一個任務來優化下面的sql查詢。目前查詢超時並導致大量阻塞。我剛開始使用t-sql，所以請幫助我優化查詢。

select ExcludedID 
from OfferConditions with (NoLock) 
where OfferID = 27251 
    and ExcludedID in (210,223,409,423,447,480,633,...lots and lots of these..., 
    13346,13362,13380,13396,13407,1,2) 

union 

select CustomerGroupID as ExcludedID 
from CPE_IncentiveCustomerGroups ICG with (NoLock) 
inner join CPE_RewardOptions RO with (NoLock) 
on RO.RewardOptionID = ICG.RewardOptionID 
where RO.IncentiveID = 27251 
    AND ICG.Deleted = 0 and RO.Deleted = 0 and 
    and ExcludedUsers = 1 
    and CustomerGroupID in (210,223,409,423,447,480,633,...lots and lots of these..., 
    13346,13362,13380,13396,13407,1,2); 

Answer 1

解決您的問題的關鍵不是修復SQL，而是修復您的表上的索引。例如，您應該在OfferConditions表上有OfferID和ExcludedID的複合索引。

當您在其他表上創建索引時，請記住，如果該字段位於where或聯接篩選器中，它應該是您的複合索引的一部分。

Answer 2

您可以嘗試將這些ID插入臨時表並加入它而不是使用IN語句。