创建数据库快照 (Transact-SQL)Create a Database Snapshot (Transact-SQL)

08/10/2016

本文内容

适用于：Applies to: SQL ServerSQL Server(所有支持的版本)SQL ServerSQL Server (all supported versions)适用于：Applies to: SQL ServerSQL Server(所有支持的版本)SQL ServerSQL Server (all supported versions)

创建 SQL ServerSQL Server 数据库快照的唯一方式是使用 Transact-SQLTransact-SQL。The only way to create a SQL ServerSQL Server database snapshot is to use Transact-SQLTransact-SQL. SQL Server Management StudioSQL Server Management Studio 不支持创建数据库快照。does not support the creation of database snapshots.

开始之前Before You Begin

先决条件Prerequisites

可以使用任何恢复模式的源数据库必须满足以下先决条件：The source database, which can use any recovery model, must meet the following prerequisites:

服务器实例必须运行支持数据库快照的 SQL ServerSQL Server 版本。The server instance must be running an edition of SQL ServerSQL Server that supports database snapshot. 有关 SQL Server 2019 (15.x)SQL Server 2019 (15.x)中数据库快照支持的详细信息，请参阅 SQL Server 2016 各个版本支持的功能。For information about support for database snapshots in SQL Server 2019 (15.x)SQL Server 2019 (15.x), see Features Supported by the Editions of SQL Server 2016.

源数据库必须处于联机状态，除非该数据库是数据库镜像会话中的镜像数据库。The source database must be online, unless the database is a mirror database within a database mirroring session.

若要在镜像数据库中创建数据库快照，数据库必须处于同步 镜像状态。To create a database snapshot on a mirror database, the database must be in the synchronized mirroring state.

不能将源数据库配置为可缩放共享数据库。The source database cannot be configured as a scalable shared database.

源数据库不得包含 MEMORY_OPTIMIZED_DATA 文件组。The source database must not contain a MEMORY_OPTIMIZED_DATA filegroup.

重要

For information about other significant considerations, see Database Snapshots (SQL Server).

建议Recommendations

本节讨论以下最佳做法：This section discusses the following best practices:

最佳做法：命名数据库快照Best Practice: Naming Database Snapshots

创建数据库快照之前，考虑如何命名它们是非常重要的。Before creating snapshots, it is important to consider how to name them. 每个数据库快照都需要一个唯一的数据库名称。Each database snapshot requires a unique database name. 为了便于管理，数据库快照的名称可以包含标识数据库的信息，例如：For administrative ease, the name of a snapshot can incorporate information that identifies the database, such as:

源数据库的名称。The name of the source database.

表明新名称用于快照的指示信息。An indication that the new name is for a snapshot.

快照的创建日期和时间、序列号或一些其他的信息(例如一天中的某个时间)以区分给定的数据库上的连续快照。The creation date and time of the snapshot, a sequence number, or some other information, such as time of day, to distinguish sequential snapshots on a given database.

例如，假设有一系列的 AdventureWorks2012AdventureWorks2012 数据库快照。For example, consider a series of snapshots for the AdventureWorks2012AdventureWorks2012 database. 在上午 6 时和下午 6 时(基于 24 小时制)之间，Three daily snapshots are created at 6-hour intervals between 6 A.M. 以 6 个小时为间隔创建三个每日快照。and 6 P.M., based on a 24-hour clock. 每个每日快照保持 24 小时才被删除并被同一名称的新快照替换。Each daily snapshot is kept for 24 hours before being dropped and replaced by a new snapshot of the same name. 请注意，每个快照名称指明了小时，而非天：Note that each snapshot name indicates the hour, but not the day:

AdventureWorks_snapshot_0600

AdventureWorks_snapshot_1200

AdventureWorks_snapshot_1800

另外，如果这些每日快照创建的时间每天都变化，则推荐使用不太精确的命名约定，例如：Alternatively, if the creation time of these daily snapshots varies from day to day, a less precise naming convention might be preferable, for example:

AdventureWorks_snapshot_morning

AdventureWorks_snapshot_noon

AdventureWorks_snapshot_evening

最佳做法：限制数据库快照的数量Best Practice: Limiting the Number of Database Snapshots

随着时间的变化创建一系列快照可捕获源数据库的连续快照。Creating a series of snapshots over time captures sequential snapshots of the source database. 每个数据库快照会一直保存在系统中，直到被显式删除。Each snapshot persists until it is explicitly dropped. 因为每个快照会随着原始页的更新而不断增长，所以您可能想在创建新快照后通过删除旧的快照来节省空间。Because each snapshot will continue to grow as original pages are updated, you may want to conserve disk space by deleting an older snapshot after creating a new snapshot.

注意！Note! 若要还原到某个数据库快照，则需要从该数据库中删除所有其他快照。To revert to a database snapshot, you need to delete any other snapshots from that database.

最佳做法：将客户端连接到数据库快照Best Practice: Client Connections to a Database Snapshot

若要使用数据库快照，客户端需要知道它的位置。To use a database snapshot, clients need to know where to find it. 正在创建或删除另一个数据库快照时，用户可以从一个数据库快照读取。Users can read from one database snapshot while another is being created or deleted. 但是，如果用新快照替代现有快照，您需要将客户端重新定向到新快照。However, when you substitute a new snapshot for an existing one, you need to redirect clients to the new snapshot. 用户可以通过 SQL Server Management StudioSQL Server Management Studio手动连接到数据库快照。Users can manually connect to a database snapshot by means of SQL Server Management StudioSQL Server Management Studio. 但是，若要支持生产环境，您应该创建一个编程解决方案，该方案透明地将报表编写客户端定向到数据库的最新数据库快照。However, to support a production environment, you should create a programmatic solution that transparently directs report-writing clients to the latest database snapshot of the database.

权限Permissions

可创建数据库的任何用户都可以创建数据库快照；但是，若要创建镜像数据库的快照，你必须是 sysadmin 固定服务器角色的成员。Any user who can create a database can create a database snapshot; however, to create a snapshot of a mirror database, you must be a member of the sysadmin fixed server role.

如何创建数据库快照(使用 Transact-SQL)How to Create a Database Snapshot (Using Transact-SQL)

创建数据库快照To create a database snapshot

有关此过程的示例，请参阅本节后面的 示例 (Transact-SQL)。For an example of this procedure, see Examples (Transact-SQL), later in this section.

根据源数据库的当前大小，确保有足够的磁盘空间存放数据库快照。Based on the current size of the source database, ensure that you have sufficient disk space to hold the database snapshot. 数据库快照的最大大小为创建快照时源数据库的大小。The maximum size of a database snapshot is the size of the source database at snapshot creation.

使用 AS SNAPSHOT OF 子句对文件执行 CREATE DATABASE 语句。Issue a CREATE DATABASE statement on the files using the AS SNAPSHOT OF clause. 创建快照需要指定源数据库的每个数据库文件的逻辑名称。Creating a snapshot requires specifying the logical name of every database file of the source database. 语法如下所示：The syntax is as follows:

CREATE DATABASE database_snapshot_nameCREATE DATABASE database_snapshot_name

ONON

((

NAME =logical_file_name,NAME =logical_file_name,

FILENAME ='os_file_name'FILENAME ='os_file_name'

) [ ,...n ]) [ ,...n ]

AS SNAPSHOT OF source_database_nameAS SNAPSHOT OF source_database_name

[;][;]

其中，source_database_name 是源数据库，logical_file_name 是引用该文件时在 SQL Server 中使用的逻辑名称，os_file_name 是创建该文件时操作系统使用的路径和文件名，database_snapshot_name 是将数据库恢复到的快照的名称。Where source_**database_name is the source database, logical_file_name i s the logical name used in SQL Server when referencing the file, os_file_name is the path and file name used by the operating system when you create the file, and database_snapshot_name is the name of the snapshot to which you want to revert the database. For a full description of this syntax, see CREATE DATABASE (SQL Server Transact-SQL).

备注

创建数据库快照时，CREATE DATABASE 语句中不允许有日志文件、脱机文件、还原文件和不起作用的文件。When you create a database snapshot, log files, offline files, restoring files, and defunct files are not allowed in the CREATE DATABASE statement.

示例 (Transact-SQL)Examples (Transact-SQL)

备注

示例中使用的扩展名 .ss 是随意选择的。The .ss extension used in the examples is arbitrary.

本部分包含以下示例：This section contains the following examples:

A.A. 对 AdventureWorks 数据库创建快照Creating a snapshot on the AdventureWorks database

此示例对 AdventureWorks 数据库创建数据库快照。This example creates a database snapshot on the AdventureWorks database. 快照名称 AdventureWorks_dbss_1800及其稀疏文件的名称 AdventureWorks_data_1800.ss指明了创建时间 6 P.M.(1800 小时)。The snapshot name, AdventureWorks_dbss_1800, and the file name of its sparse file, AdventureWorks_data_1800.ss, indicate the creation time, 6 P.M (1800 hours).

CREATE DATABASE AdventureWorks_dbss1800 ON

( NAME = AdventureWorks, FILENAME =

'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Data\AdventureWorks_data_1800.ss' )

AS SNAPSHOT OF AdventureWorks;

GO

B.B. 对 Sales 数据库创建快照Creating a snapshot on the Sales database

此示例对 sales_snapshot1200数据库创建数据库快照 Sales 。This example creates a database snapshot, sales_snapshot1200, on the Sales database. This database was created in the example, "Creating a database that has filegroups," in CREATE DATABASE (SQL Server Transact-SQL).

--Creating sales_snapshot1200 as snapshot of the

--Sales database:

CREATE DATABASE sales_snapshot1200 ON

( NAME = SPri1_dat, FILENAME =

'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\data\SPri1dat_1200.ss'),

( NAME = SPri2_dat, FILENAME =

'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\data\SPri2dt_1200.ss'),

( NAME = SGrp1Fi1_dat, FILENAME =

'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\mssql\data\SG1Fi1dt_1200.ss'),

( NAME = SGrp1Fi2_dat, FILENAME =

'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\data\SG1Fi2dt_1200.ss'),

( NAME = SGrp2Fi1_dat, FILENAME =

'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\data\SG2Fi1dt_1200.ss'),

( NAME = SGrp2Fi2_dat, FILENAME =

'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\data\SG2Fi2dt_1200.ss')

AS SNAPSHOT OF Sales;

GO

相关任务Related Tasks

另请参阅See Also