SQL SERVER Which Query is faster Which query is faster:
Query A
SELECT I.ItemName
FROM Location L
INNER JOIN Items I ON I.LocationID = L.LocationID
WHERE L.LocationID = 1

Execution Plan

Query B
SELECT ItemName
FROM Items 
WHERE ItemID IN (
SELECT ItemID
FROM  Items
WHERE LocationID = 1)

Execution Plan
Neither. Try:
SELECT I.ItemName
FROM Items I
WHERE I.LocationID = 1

...and add a covering index on LocationID with INCLUDE column ItemName  .