Is a JOIN more/less efficient than EXISTS IN when no data is needed from the second table?
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by twpc
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Published on 2010-03-22T12:01:31Z
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2010/03/22
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I need to look up all households with orders. I don't care about the data of the order at all, just that it exists.
Is it more efficient to say something like this:
SELECT HouseholdID, LastName, FirstName, Phone
FROM Households
INNER JOIN Orders ON Orders.HouseholdID = Households.HouseholdID
or this:
SELECT HouseholdID, LastName, FirstName, Phone
FROM Households
WHERE EXISTS
(SELECT HouseholdID
FROM Orders
WHERE Orders.HouseholdID = Households.HouseholdID)
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