我有下面的SQL查詢運行非常緩慢。我看了一下執行計劃,聲稱在Files.OrderId上進行排序是成本最高的操作(53%)。爲什麼會發生這種情況,如果我沒有通過OrderId在任何地方訂購?我最好在File.OrderId上創建索引嗎?爲什麼我的執行計劃中會出現排序?
Execution plan如果有人有興趣。
with custOrders as
(
SELECT c.firstName + ' ' + c.lastname as Customer, c.PartnerId , c.CustomerId,o.OrderId,o.CreateDate, c.IsPrimary
FROM Customers c
LEFT JOIN CustomerRelationships as cr
ON c.CustomerId = cr.PrimaryCustomerId
INNER JOIN Orders as o
ON c.customerid = o.customerid
OR (cr.secondarycustomerid IS NOT NULL AND o.customerid = cr.secondarycustomerid)
where c.createdate >= @FromDate + ' 00:00'
AND c.createdate <= @ToDate + ' 23:59'
),
temp as
(
SELECT Row_number()
OVER (
ORDER BY c.createdate DESC) AS 'row_number',
c.customerid as customerId,
c.partnerid as partnerId,
c.Customer,
c.orderid as OrderId,
c.createdate as CreateDate,
Count(f.orderid) AS FileCount,
dbo.Getparentcustomerid(c.isprimary, c.customerid) AS ParentCustomerId,
au.firstname + ' ' + au.lastname AS Admin,
'' as blank,
0 as zero
FROM custOrders c
INNER JOIN files f
ON c.orderid = f.orderid
INNER JOIN admincustomers ac
ON c.customerid = ac.customerid
INNER JOIN adminusers au
ON ac.adminuserid = au.id
INNER JOIN filestatuses s
ON f.statusid = s.statusid
WHERE ac.adminuserid IS NOT NULL
AND f.statusid NOT IN (5, 6)
GROUP BY c.customerid,
c.partnerid,
c.Customer,
c.isprimary,
c.orderid,
c.createdate,
au.firstname,
au.lastname
)
*錯誤在驗證源XML * – Kermit
是的,我看到了。它真的有所作爲嗎?你仍然可以看到XML ... –
不是'OVER'意味着什麼? – Kermit