Sql server 索引插入期间的多个表假脱机（即时假脱机）_Sql Server_Tsql_Sql Server 2008 R2_Query Optimization

Sql server 索引插入期间的多个表假脱机（即时假脱机）

sql-server tsql sql-server-2008-r2

Sql server 索引插入期间的多个表假脱机（即时假脱机）,sql-server,tsql,sql-server-2008-r2,query-optimization,Sql Server,Tsql,Sql Server 2008 R2,Query Optimization,我正在执行几百行的简单插入，例如： INSERT INTO Foo SELECT * FROM Bar 该表有几个二级索引。禁用这些索引后，查询几乎立即运行。启用辅助索引后，查询运行需要几秒钟，子树成本相对较高问题在于，对于每个辅助索引，数据库都会执行以下操作：物理操作：逻辑操作：其缓存位置：目标表中的所有列（当它只需要所需的值时）多次值（而不是一次）虽然了解SQL Server（2008 R2 SP2）为什么认为需要这样做可能很有趣，但我真正需要的是一种方法，使在实时

我正在执行几百行的简单插入，例如：

INSERT INTO Foo
SELECT * FROM Bar

该表有几个二级索引。禁用这些索引后，查询几乎立即运行。启用辅助索引后，查询运行需要几秒钟，子树成本相对较高

问题在于，对于每个辅助索引，数据库都会执行以下操作：

物理操作：
逻辑操作：

其缓存位置：

目标表中的所有列（当它只需要所需的值时）
多次值（而不是一次）

虽然了解SQL Server（2008 R2 SP2）为什么认为需要这样做可能很有趣，但我真正需要的是一种方法，使在实时服务器中插入100行不需要6秒钟

真正、真正、可怕的部分是，对于every表假脱机，SQL Server会缓存every列、every时间的值：

这就是逻辑IO

如果没有这些有问题的索引更新，60000行的完整导入只需一两秒钟
有了这些索引，完整的导入几乎需要几十分钟

复制步骤当然，我的real

AuditLog

表包含4M行。但我们可以使用空的AuditLog表以高子树成本复制完全相同的运算符：

CREATE TABLE [dbo].[AuditLog](
    [AuditLogID] [int] IDENTITY(216,1) NOT NULL,
    [ChangeDate] [datetime] NOT NULL CONSTRAINT [DF_AuditLog_ChangeDate]  DEFAULT (getdate()),
    [RowGUID] [uniqueidentifier] NOT NULL,
    [ChangeType] [varchar](50) NOT NULL,
    [TableName] [varchar](128) NOT NULL,
    [FieldName] [varchar](128) NOT NULL,
    [OldValue] [varchar](max) NULL,
    [NewValue] [varchar](max) NULL,
    [SystemUser] [varchar](128) NULL CONSTRAINT [DF_AuditLog_SystemUser]  DEFAULT (suser_sname()),
    [Username] [varchar](128) NOT NULL CONSTRAINT [DF_AuditLog_Username]  DEFAULT (user_name()),
    [Hostname] [varchar](50) NOT NULL CONSTRAINT [DF_AuditLog_Hostname]  DEFAULT (host_name()),
    [AppName] [varchar](128) NULL CONSTRAINT [DF_AuditLog_AppName]  DEFAULT (app_name()),
    [UserGUID] [uniqueidentifier] NULL,
    [TagGUID] [uniqueidentifier] NULL,
    [Tag] [varchar](max) NULL,
    [timestamp] [timestamp] NOT NULL,
    CONSTRAINT [PK_AuditLog] PRIMARY KEY CLUSTERED ([AuditLogID] ASC)
)

我们有痛苦指数：

SET ANSI_PADDING OFF
GO
/****** Object:  Index [IX_AuditLog_ChangeDate]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_ChangeDate] ON [dbo].[AuditLog]
(
    [ChangeDate] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
SET ANSI_PADDING ON

GO
/****** Object:  Index [IX_AuditLog_FieldName]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_FieldName] ON [dbo].[AuditLog]
(
    [FieldName] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
SET ANSI_PADDING ON

GO
/****** Object:  Index [IX_AuditLog_LastRowActionByTable]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_LastRowActionByTable] ON [dbo].[AuditLog]
(
    [TableName] ASC,
    [ChangeType] ASC,
    [RowGUID] ASC,
    [UserGUID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
/****** Object:  Index [IX_AuditLog_RowGUID]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_RowGUID] ON [dbo].[AuditLog]
(
    [RowGUID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
SET ANSI_PADDING ON

GO
/****** Object:  Index [IX_AuditLog_RowInsertedByUserGUID]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_RowInsertedByUserGUID] ON [dbo].[AuditLog]
(
    [ChangeType] ASC,
    [RowGUID] ASC,
    [UserGUID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
/****** Object:  Index [IX_AuditLog_RowLastModifiedByUserGUID]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_RowLastModifiedByUserGUID] ON [dbo].[AuditLog]
(
    [RowGUID] ASC,
    [ChangeDate] ASC,
    [UserGUID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
SET ANSI_PADDING ON

GO
/****** Object:  Index [IX_AuditLog_TableName]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_TableName] ON [dbo].[AuditLog]
(
    [TableName] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
/****** Object:  Index [IX_AuditLog_TagGUID]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_TagGUID] ON [dbo].[AuditLog]
(
    [TagGUID] ASC,
    [RowGUID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
/****** Object:  Index [IX_AuditLog_UserGUID]    Script Date: 11/17/2016 2:58:43 PM ******/
CREATE NONCLUSTERED INDEX [IX_AuditLog_UserGUID] ON [dbo].[AuditLog]
(
    [ChangeDate] ASC,
    [UserGUID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]

然后我们创建插入：

INSERT INTO AuditLog(
            RowGUID, 
            ChangeType, 
            UserGUID, 
            TableName, 
            FieldName, 
            TagGUID, 
            Tag)

SELECT
        'E5E31EDD-7D39-47FD-BCFF-4B7044AC433D',
        'INSERTED',
        '4A2FDACD-0209-403B-ADBC-1B8A68E90350', --UserGUID
        'Customers', --TableName
        '', --FieldName
        '7A74267D-64F9-44D7-A1D7-1490A66136BF', --TagGUID
        'Contoso'
FROM (
    --A dummy derived table that lets us select the above row 100 times
    SELECT TOP 400 (a.Number * 256) + b.Number AS Number
    FROM (
        SELECT number FROM master..spt_values WHERE type = 'P' AND number <= 255) a (Number),
        (SELECT number FROM master..spt_values WHERE type = 'P' AND number <= 255) b (Number)
) dt

在以下情况下执行6秒的4.55秒：

在等待I/O操作完成时发生。此等待类型通常表示非数据页I/O。数据页I/O完成等待显示为PAGEIOLATCH_*waitis

你说的非冗余索引？无排序警告批处理的SQL Server探查器结果

持续时间：7401毫秒

阅读：233597

写入：17077

CPU：1141毫秒

没有排序警告。也没有任何注意，位图警告，执行警告，哈希警告，缺少列统计信息，缺少连接谓词，排序警告，用户错误消息

所有索引都已重建。所有统计数据都已更新。
您有重叠和冗余索引的问题

这个qry会有帮助：
这是一个对一个狭窄的。对400行进行假脱机并对其进行6次排序不会在6秒的顺序上产生任何影响。一定还有别的事。你看到了什么样的等待类型？嗯，好吧，它与排序和假脱机等相关，但很难想象，在描述的数据量如此之大的情况下，事情会如此缓慢。假脱机只发生一次，然后重复6次。您在探查器中看到排序警告了吗？您的磁盘显然太忙了，无法完成这样一项平凡的任务。除了SQL Server之外，是否还有其他活动会给他们带来压力？还是并行运行的维护作业？顺便说一句，我在你的索引中看到很多guid。他们的填充因子呢？也许你遇到了页面分割？
| Wait Type | Wait Time (s) | Wait Count | |----------------|---------------|------------| | IO_COMPLETION | 4.55 s | 211 | | WRITELOG | 0.79 s | 37 | | PAGEIOLATCH_UP | 0.36 s | 1 | | PAGELATCH_UP | 0.09 s | 2 | | PAGEIOLATCH_EX | 0.07 s | 4 |

| Index Name | Columns | Index Entry Size | |---------------------------------------|------------------------------------------|--------------------------| | IX_AuditLog_ChangeDate | ChangeDate | 12 bytes per entry | | IX_AuditLog_UserGUID | ChangeDate, UserGUID | 28 bytes per entry | | IX_AuditLog_FieldName | FieldName | 4 bytes per entry (avg) | | IX_AuditLog_TableName | TableName | 13 bytes per entry (avg) | | IX_AuditLog_LastRowActionByTable | TableName, ChangeType, RowGUID, UserGUID | 52 bytes per entry (avg) | | IX_AuditLog_RowGUID | RowGUID | 20 bytes per entry | | IX_AuditLog_RowLastModifiedByUserGUID | RowGUID, ChangeDate, UserGUID | 44 bytes per entry | | IX_AuditLog_RowInsertedByUserGUID | ChangeType, RowGUID, UserGUID | 43 bytes per entry (avg) | | IX_AuditLog_TagGUID | TagGUID, RowGUID | 36 bytes per entry |