Hi Tim,

I had a query similar to yours.. And it took a very
Long time to run.. The culprit was the sub-query.
Try replacing the subquery with an inner join.. Also
Change count(*) to count one particular field.. 
Eg: COUNT(TransactionID). Some table indexes might also
Speed things up somewhat..

Hope this is of some use..
Adam

-----Original Message-----
From: Tim Rox [mailto:[EMAIL PROTECTED] 
Sent: Friday, July 25, 2003 1:31 PM
To: CFAussie Mailing List
Subject: [cfaussie] OT - SQL Mindbender


hi there,

Am having some SQL headaches with quite a big database.

I want to find the top 100 spenders during the previous month for each
of a number of 'clubs'.

I have a table full of transactions with a clubID, customerID, date,
amount of the transaction.

Unfortunately I can't use cold fusion for this one, so all the hard work
has to be done in SQL.

My attempt below seems to take an indefinate amount of time. Any
suggestions on how it could be done more efficiently? I feel like the
subquery is duplicating a lot of work that the main query is doing.


SELECT  ClubID, CustomerID, COUNT(*) AS Transactions,
SUM(transactionValue)
AS TotalValue

FROM            Transactions t1

WHERE   DATEPART(month, transactionDate)=DATEPART(month, DATEADD(month,
-1,
GETDATE())
AND             DATEPART(year, transactionDate)=DATEPART(year,
DATEADD(month, -1,
GETDATE())

AND     MemberID IS IN (SELECT TOP 100 CustomerID,
                        FROM    Transactions
                        WHERE   DATEPART(month,
transactionDate)=DATEPART(month,
DATEADD(month, -1, GETDATE()))
                        AND     DATEPART(year,
transactionDate)=DATEPART(year, DATEADD(month, -1,
GETDATE()))
                        AND     ClubID = t1.ClubID
                        GROUP BY CustomerID
                        ORDER BY SUM(transactionValue) DESC)

GROUP BY ClubID, CustomerID

ORDER BY ClubID, totalValue DESC

----------------------
Tim Rox
Newgency Pty Ltd
2a Broughton St
Paddington 2021
Sydney, Australia
Ph (02) 9331 2133
Fax (02) 9331 5199
Mobile: 0411 512 454
http://www.newgency.com/


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