Sql server 执行速度极慢的选择
我有一个包含7526511条记录的表,其定义如下:Sql server 执行速度极慢的选择,sql-server,performance,Sql Server,Performance,我有一个包含7526511条记录的表,其定义如下: /****** Object: Table [dbo].[LogSearches] Script Date: 12/07/2009 09:23:14 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[LogSearches]( [ID] [numeric](18, 0) ID
/****** Object: Table [dbo].[LogSearches] Script Date: 12/07/2009 09:23:14 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[LogSearches](
[ID] [numeric](18, 0) IDENTITY(1,1) NOT NULL,
[Acct_ID] [int] NULL,
[RecordCount] [int] NOT NULL,
[PageNumber] [int] NOT NULL,
[Site_ID] [int] NOT NULL,
[SearchAPI] [bit] NOT NULL,
[FormSearch] [bit] NOT NULL,
[IPAddress] [varchar](15) NOT NULL,
[Domain] [nvarchar](150) NOT NULL,
[ScriptName] [nvarchar](500) NOT NULL,
[QueryString] [varchar](max) NULL,
[Referer] [nvarchar](1024) NOT NULL,
[SearchString] [nvarchar](max) NOT NULL,
[UserAgent] [nvarchar](2048) NULL,
[Processed] [datetime] NOT NULL,
[Created] [datetime] NOT NULL,
[IntegerIP] [int] NULL,
CONSTRAINT [PK_LogSearches] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
ALTER TABLE [dbo].[LogSearches] ADD CONSTRAINT [DF_LogSearches_Processed] DEFAULT (getdate()) FOR [Processed]
GO
ALTER TABLE [dbo].[LogSearches] ADD CONSTRAINT [DF_LogSearches_Created] DEFAULT (getdate()) FOR [Created]
GO
执行计划如下所示:
StmtText StmtId NodeId Parent PhysicalOp LogicalOp Argument DefinedValues EstimateRows EstimateIO EstimateCPU AvgRowSize TotalSubtreeCost OutputList Warnings Type Parallel EstimateExecutions
---------------------------------------------------------------------------------------- ----------- ----------- ----------- ------------------------------ ------------------------------ -------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ------------- ------------- ------------- ----------- ---------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------- ---------------------------------------------------------------- -------- ------------------
SELECT TOP 1 * FROM LogSearches 1 1 0 NULL NULL 1 NULL 1 NULL NULL NULL 0.0032832 NULL NULL SELECT 0 NULL
|--Top(TOP EXPRESSION:((1))) 1 2 1 Top Top TOP EXPRESSION:((1)) NULL 1 0 1E-07 11848 0.0032832 [LOALogs].[dbo].[LogSearches].[ID], [LOALogs].[dbo].[LogSearches].[Acct_ID], [LOALogs].[dbo].[LogSearches].[RecordCount], [LOALogs].[dbo].[LogSearches].[PageNumber], [LOALogs].[dbo].[LogSearches].[Site_ID], [LOALogs].[dbo].[LogSearches].[SearchAPI], [LOALo NULL PLAN_ROW 0 1
|--Clustered Index Scan(OBJECT:([LOALogs].[dbo].[LogSearches].[PK_LogSearches])) 1 3 2 Clustered Index Scan Clustered Index Scan OBJECT:([LOALogs].[dbo].[LogSearches].[PK_LogSearches]) [LOALogs].[dbo].[LogSearches].[ID], [LOALogs].[dbo].[LogSearches].[Acct_ID], [LOALogs].[dbo].[LogSearches].[RecordCount], [LOALogs].[dbo].[LogSearches].[PageNumber], [LOALogs].[dbo].[LogSearches].[Site_ID], [LOALogs].[dbo].[LogSearches].[SearchAPI], [LOALo 1 2956.71 8.279319 11848 0.0032831 [LOALogs].[dbo].[LogSearches].[ID], [LOALogs].[dbo].[LogSearches].[Acct_ID], [LOALogs].[dbo].[LogSearches].[RecordCount], [LOALogs].[dbo].[LogSearches].[PageNumber], [LOALogs].[dbo].[LogSearches].[Site_ID], [LOALogs].[dbo].[LogSearches].[SearchAPI], [LOALo NULL PLAN_ROW 0 1
(3 row(s) affected)
当我运行查询时,它不会在任何合理的时间范围内完成。我让查询运行了超过5分钟,但它仍然没有返回我请求的一行。这种类型的慢速选择性能会对数据库产生其他影响,例如使我们很难摆脱不再需要的行
你知道我的瓶颈在哪里吗?98 gig数据库及其日志在SQL Server 2008上的4磁盘RAID 10上运行,驱动器上有超过100 gig的可用空间。是否检查了是否存在阻塞问题?是否可以创建另一个具有所需结构的表,并在其中复制/“泵送”数据,然后删除旧表并重命名新表?对于特定的id范围,您可能需要“批量”执行此操作:
INSERT INTO LogSearches_new ... SELECT * FROM LogSearches WHERE ID BETWEEN 1 AND 999999
您确定正在选择的行没有被另一个进程锁定的行/页/db阻止吗?尝试将with(NoLock)添加到查询的末尾,看看这是否有助于在使用(NoLock)时返回它,它确实会随NoLock返回。看来我犯了个错误,因为我已经和这张桌子打了这么久的交道。该死的。长的清除不再需要的行花费了我很多时间。当危机结束时,如果您使用SQL 2005/8,您可能希望查看日志文件的分区表;您可以对数据进行分区,这样只需稍加维护,当前月份的日志数据就可以放入一个表中,其余的则放在另一个表中。可以是一个非常有用的工具;如果你在enterprise上,你可以设置为离线或只读,这会更好。是的,我对按日期划分表很感兴趣,我只需要找出如何使用它。那里的文档似乎太过技术化了,应该是一些非常简单的设置。过去几天我一直在与这个表斗争,但这次没有。看来这毕竟是个问题。我在尝试从此表中删除记录时遇到了持续的问题,并错误地假设它是相同的旧内容。不幸的是,该解决方案导致的问题与我尝试删除时的原始删除问题一样多:-(.我想我有磁盘I/O问题需要解决以加快速度。已运行PerfMon 24小时,所以我们将看看它有什么要说的。