How can I speed up this view which sums a load of quote line rows?
I am writing a view to show quote totals based on summing the values in a quote line table. I need to restrict the view to only show quotes for customers of a particular 'pricetype'. However when I do this 开发者_如何学运维the view slows down a lot.
SQL to sum the prices
SELECT dbo.quoteline.qid, SUM((dbo.pricelist.listprice - dbo.quoteline.voff) * dbo.quoteline.quantity) AS total
FROM dbo.quoteline LEFT OUTER JOIN dbo.pricelist ON dbo.quoteline.prodcode = dbo.pricelist.prodcode GROUP BY dbo.quoteline.qid
SQL once 'pricetype' constraint is added
SELECT dbo.quoteline.qid, SUM((dbo.pricelist.listprice - dbo.quoteline.voff) * dbo.quoteline.quantity) AS total
FROM dbo.pricelist RIGHT OUTER JOIN
dbo.client RIGHT OUTER JOIN
dbo.quote ON dbo.client.cid = dbo.quote.cid RIGHT OUTER JOIN
dbo.quoteline ON dbo.quote.qid = dbo.quoteline.qid ON dbo.pricelist.prodcode = dbo.quoteline.prodcode
WHERE (dbo.client.pricetype = 'V')
GROUP BY dbo.quoteline.qid
Maybe its late and I am having a moment but any help here would be gratefully appreciated.
Two things: First, can you put an index on the dbo.client.pricetype column without it interfering with inserts/updates? Secondly, inner joins are generally faster than outer joins and since your results and where clause depend on the other tables, I suspect you will want to do inner joins anyways unless there are NULL records you need back from your view. Try this following query to see if it gets you the results you need:
SELECT dbo.quoteline.qid, SUM((dbo.pricelist.listprice - dbo.quoteline.voff) * dbo.quoteline.quantity) AS total
FROM dbo.quoteline
INNER JOIN dbo.pricelist ON dbo.quoteline.prodcode = dbo.pricelist.prodcode
INNER JOIN dbo.quote ON dbo.quote.qid = dbo.quoteline.qid
INNER JOIN dbo.client ON dbo.client.cid = dbo.quote.cid
WHERE (dbo.client.pricetype = 'V')
GROUP BY dbo.quoteline.qid
What does happen if you do it like this :
SELECT dbo.quoteline.qid, SUM((dbo.pricelist.listprice - dbo.quoteline.voff) * dbo.quoteline.quantity) AS total
FROM dbo.pricelist RIGHT OUTER JOIN
dbo.client ON dbo.client.pricetype = 'V' RIGHT OUTER JOIN
dbo.quote ON dbo.client.cid = dbo.quote.cid RIGHT OUTER JOIN
dbo.quoteline ON dbo.quote.qid = dbo.quoteline.qid AND dbo.pricelist.prodcode = dbo.quoteline.prodcode
GROUP BY dbo.quoteline.qid
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