内部连接表和视图时性能显着降低
我在我的sql服务器中有三个视图：
CREATE VIEW [dbo].[v_CompanyLabelCreate]
AS
SELECT
c.Id AS Id,
c.[Name] AS CompanyName,
CASE WHEN r.ApprovedPatentCreativeApplication > 2 OR r.ApprovedCopyRightBookApplication + r.ApprovedCopyRightSoftwareApplication > 4 OR NumberInProduction + NumberNotInProduction > 10 THEN N'创造型'
ELSE NULL END AS Label
FROM Company c INNER JOIN ResearchInfo r ON c.Id = r.CompanyID
WHERE c.Submitted = 1
CREATE VIEW [dbo].[v_CompanyLabelHighPotential]
AS
SELECT
c.Id AS Id,
c.[Name] AS CompanyName,
CASE WHEN si1.Income >= 1000000 AND si2.Income <> 0 AND ((si1.Income -si2.Income)/si2.Income) >= 1 THEN N'潜力型'
WHEN n1.TotalProfit >= 500000 AND n2.TotalProfit <> 0 AND ((n1.TotalProfit - n2.TotalProfit)/n2.TotalProfit) >= 1 THEN N'潜力型'
WHEN nfa1.AssetsTotal >= 5000000 AND nfa2.AssetsTotal <> 0 AND ((nfa1.AssetsTotal - nfa2.AssetsTotal)/nfa2.AssetsTotal) >= 1 THEN N'潜力型'
ELSE NULL END AS Label
FROM Company c INNER JOIN SaleIncome si1 ON c.Id = si1.CompanyID AND si1.YearQuarterID = 2
INNER JOIN SaleIncome si2 ON c.Id = si2.CompanyID AND si2.YearQuarterID = 1
INNER JOIN NetProfit n1 ON c.Id = n1.CompanyID AND n1.YearQuarterID = 2
INNER JOIN NetProfit n2 ON c.Id = n2.CompanyID AND n2.YearQuarterID = 1
INNER JOIN NonFloatingAsset nfa1 ON c.Id = nfa1.CompanyID AND nfa1.YearQuarterID = 2
INNER JOIN NonFloatingAsset nfa2 ON c.Id = nfa2.CompanyID AND nfa2.YearQuarterID = 1
WHERE c.Submitted = 1
CREATE VIEW [dbo].[v_CompanyLabelHighTotalPolicies]
AS
SELECT
c.Id AS Id,
c.[Name] AS CompanyName,
CASE WHEN p.NumberOfPolicies >= 4 AND cp.PolicyID IS NOT NULL THEN N'政策大户'
ELSE NULL END AS Label
FROM Company c LEFT JOIN (SELECT CompanyID, COUNT(*) AS NumberOfPolicies FROM CompanyPolicy GROUP BY CompanyID) p ON c.Id = p.CompanyID
LEFT JOIN (SELECT CompanyID, PolicyID FROM CompanyPolicy WHERE PolicyID = 7) cp ON c.Id = cp.CompanyID
WHERE c.Submitted = 1
当我运行一个内部连接这三个视图的select查询时：
select *
from v_CompanyLabelCreate clc
INNER JOIN v_CompanyLabelHighPotential clhp ON clc.Id = clhp.Id
INNER JOIN v_CompanyLabelHighTotalPolicies chtp ON clc.Id = chtp.Id
它快速而流畅。 然而，当我尝试运行一个select查询时，这些查询与其他表中的这三个视图进行内联：
select *
FROM Company c
INNER JOIN BasicInfo b ON c.Id = b.CompanyID
INNER JOIN CompanyDimension cd ON c.Id = cd.CompanyID
INNER JOIN TotalProfit t ON c.Id = t.CompanyID AND t.YearQuarterID = 2
INNER JOIN SaleCost sc ON c.Id = sc.CompanyID AND sc.YearQuarterID = 2
INNER JOIN CompanyFinancialIndex cfi ON c.Id = cfi.CompanyID AND cfi.YearQuarterID = 6
INNER JOIN SaleIncome si1 ON c.Id = si1.CompanyID AND si1.YearQuarterID = 2
INNER JOIN SaleIncome si2 ON c.Id = si2.CompanyID AND si2.YearQuarterID = 1
INNER JOIN NetProfit n1 ON c.Id = n1.CompanyID AND n1.YearQuarterID = 2
INNER JOIN NetProfit n2 ON c.Id = n2.CompanyID AND n2.YearQuarterID = 1
INNER JOIN v_CompanyLabelCreate clc ON c.Id = clc.Id
INNER JOIN v_CompanyLabelHighPotential clhp ON clc.Id = clhp.Id
INNER JOIN v_CompanyLabelHighTotalPolicies chtp ON clc.Id = chtp.Id
WHERE c.Submitted = 1
它看起来像得到结果需要永久（下载执行计划：执行计划）。 现在，如果我只是运行查询而没有内部加入这样的三个视图：
select *
FROM Company c
INNER JOIN BasicInfo b ON c.Id = b.CompanyID
INNER JOIN CompanyDimension cd ON c.Id = cd.CompanyID
INNER JOIN TotalProfit t ON c.Id = t.CompanyID AND t.YearQuarterID = 2
INNER JOIN SaleCost sc ON c.Id = sc.CompanyID AND sc.YearQuarterID = 2
INNER JOIN CompanyFinancialIndex cfi ON c.Id = cfi.CompanyID AND cfi.YearQuarterID = 6
INNER JOIN SaleIncome si1 ON c.Id = si1.CompanyID AND si1.YearQuarterID = 2
INNER JOIN SaleIncome si2 ON c.Id = si2.CompanyID AND si2.YearQuarterID = 1
INNER JOIN NetProfit n1 ON c.Id = n1.CompanyID AND n1.YearQuarterID = 2
INNER JOIN NetProfit n2 ON c.Id = n2.CompanyID AND n2.YearQuarterID = 1
WHERE c.Submitted = 1
它又快又平滑。
关于使用的表格：
你也可以有一个错过的索引问题，但你的查询有点复杂。 您可以尝试使用cte表来降低复杂性（您需要字段名称在CTE中是唯一的）：
WITH cte_tb1
AS (SELECT * -- UNIQUE NAMES FIELDS IS REQUIRED
FROM company c
INNER JOIN basicinfo b
ON c.id = b.companyid
INNER JOIN companydimension cd
ON c.id = cd.companyid
INNER JOIN totalprofit t
ON c.id = t.companyid
AND t.yearquarterid = 2
INNER JOIN salecost sc
ON c.id = sc.companyid
AND sc.yearquarterid = 2
INNER JOIN companyfinancialindex cfi
ON c.id = cfi.companyid
AND cfi.yearquarterid = 6
INNER JOIN saleincome si1
ON c.id = si1.companyid
AND si1.yearquarterid = 2
INNER JOIN saleincome si2
ON c.id = si2.companyid
AND si2.yearquarterid = 1
INNER JOIN netprofit n1
ON c.id = n1.companyid
AND n1.yearquarterid = 2
INNER JOIN netprofit n2
ON c.id = n2.companyid
AND n2.yearquarterid = 1
WHERE c.submitted = 1),
cte_tb2
AS (SELECT * -- UNIQUE NAMES FIELDS IS REQUIRED
FROM v_companylabelcreate clc
INNER JOIN v_companylabelhighpotential clhp
ON clc.id = clhp.id
INNER JOIN v_companylabelhightotalpolicies chtp
ON clc.id = chtp.id)
SELECT *
FROM cte_tb1 a
INNER JOIN cte_tb2 b
ON a.id = b.id
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