SQL SERVER 哪个查询更快
Ali*_*Ali 7 sql-server sql-server-2017
哪个查询更快：
查询 A
SELECT I.ItemName
FROM Location L
INNER JOIN Items I ON I.LocationID = L.LocationID
WHERE L.LocationID = 1
执行计划
查询 B
SELECT ItemName
FROM Items
WHERE ItemID IN (
SELECT ItemID
FROM Items
WHERE LocationID = 1)
执行计划
Rob*_*ley 12
两者都不。尝试：
SELECT I.ItemName
FROM Items I
WHERE I.LocationID = 1
...并在INCLUDE 列上添加覆盖索引 。LocationIDItemName