我有20万行Patient
和Person
表,查询需要30秒才能执行。
在Person
表中,我定义了主键(并聚集索引)为PersonId
,在Patient
表中则为PatientId
。这里还有什么可以做来改善我的程序性能呢?
我是数据库开发方面的新手。我只知道基本的SQL语句。而且不确定SQL Server是否可以快速处理20万行数据。
完整的动态过程可以在https://github.com/Padayappa/SQLProblem/blob/master/Performance上看到。
有人处理过像这样的大量数据吗?我该如何提高性能?
DECLARE @return_value int,
@unitRows bigint,
@unitPages int,
@TenantId int,
@unitItems int,
@page int
SET @TenantId = 1
SET @unitItems = 20
SET @page = 1
DECLARE @PatientSearch TABLE(
[PatientId] [bigint] NOT NULL,
[PatientIdentifier] [nvarchar](50) NULL,
[PersonNumber] [nvarchar](20) NULL,
[FirstName] [nvarchar](100) NOT NULL,
[LastName] [nvarchar](100) NOT NULL,
[ResFirstName] [nvarchar](100) NOT NULL,
[ResLastName] [nvarchar](100) NOT NULL,
[AddFirstName] [nvarchar](100) NOT NULL,
[AddLastName] [nvarchar](100) NOT NULL,
[Address] [nvarchar](255) NULL,
[City] [nvarchar](50) NULL,
[State] [nvarchar](50) NULL,
[ZipCode] [nvarchar](20) NULL,
[Country] [nvarchar](50) NULL,
[RowNumber] [bigint] NULL
)
INSERT INTO @PatientSearch SELECT PAT.PatientId
,PAT.PatientIdentifier
,PER.PersonNumber
,PER.FirstName
,PER.LastName
,RES_PER.FirstName AS ResFirstName
,RES_PER.LastName AS ResLastName
,ADD_PER.FirstName AS AddFirstName
,ADD_PER.LastName AS AddLastName
,PER.Address
,PER.City
,PER.State
,PER.ZipCode
,PER.Country
,ROW_NUMBER() OVER (ORDER BY PAT.PatientId DESC) AS RowNumber
FROM dbo.Patient AS PAT
INNER JOIN dbo.Person AS PER
ON PAT.PersonId = PER.PersonId
INNER JOIN dbo.Person AS RES_PER
ON PAT.ResponsiblePersonId = RES_PER.PersonId
INNER JOIN dbo.Person AS ADD_PER
ON PAT.AddedBy = ADD_PER.PersonId
INNER JOIN dbo.Booking AS B
ON PAT.PatientId = B.PatientId
WHERE PAT.TenantId = @TenantId AND B.CategoryId = @CategoryId
GROUP BY PAT.PatientId
,PAT.PatientIdentifier
,PER.PersonNumber
,PER.FirstName
,PER.LastName
,RES_PER.FirstName
,RES_PER.LastName
,ADD_PER.FirstName
,ADD_PER.LastName
,PER.Address
,PER.City
,PER.State
,PER.ZipCode
,PER.Country
;
SELECT @unitRows = @@ROWCOUNT
,@unitPages = (@unitRows / @unitItems) + 1;
SELECT *
FROM @PatientSearch AS IT
WHERE RowNumber BETWEEN (@page - 1) * @unitItems + 1 AND @unitItems * @page
#PatientSearch
)可能更好。原因是查询优化器总是假定表变量只有一行(它缺乏任何统计信息),因此如果你向表变量中插入大量行,则性能会非常糟糕。 - marc_sCREATE Table #PatientSearch
而不是DECLARE @patientsearch as Table
吗? - Billa