Restore a Transaction Log Backup (SQL Server)

This topic describes how to restore a transaction log backup in SQL Server 2012 by using SQL Server Management Studio or Transact-SQL.

In This Topic

• Before you begin:

  Prerequisites

  Security

• To restore a transaction log backup, using:

  SQL Server Management Studio

  Transact-SQL

• Related Tasks

Before You Begin

Prerequisites

• Backups must be restored in the order in which they were created. Before you can restore a particular transaction log backup, you must first restore the following previous backups without rolling back uncommitted transactions, that is WITH NORECOVERY:

  • The full database backup and the last differential backup, if any, taken before the particular transaction log backup. Before the most recent full or differential database backup was created, the database must have been using the full recovery model or bulk-logged recovery model.

  • All transaction log backups taken after the full database backup or the differential backup (if you restore one) and before the particular transaction log backup. Log backups must be applied in the sequence in which they were created, without any gaps in the log chain.

    For more information about transaction log backups, see Transaction Log Backups (SQL Server) and Apply Transaction Log Backups (SQL Server).

Security

Permissions

RESTORE permissions are given to roles in which membership information is always readily available to the server. Because fixed database role membership can be checked only when the database is accessible and undamaged, which is not always the case when RESTORE is executed, members of the db_owner fixed database role do not have RESTORE permissions.

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Using SQL Server Management Studio

Przestroga
The normal process of a restore is to select the log backups in the Restore Database dialog box along with the data and differential backups.

To restore a transaction log backup

1. After connecting to the appropriate instance of the Microsoft SQL Server Database Engine, in Object Explorer, click the server name to expand the server tree.

2. Expand Databases, and, depending on the database, either select a user database or expand System Databases and select a system database.

3. Right-click the database, point to Tasks, point to Restore, and then click Transaction Log, which opens the Restore Transaction Log dialog box.

   [!UWAGA]

   If Transaction Log is grayed out, you may need to restore a full or differential backup first. Use the Database backup dialog box.

4. On the General page, in the Database list box, select the name of a database. Only databases in the restoring state are listed.

5. To specify the source and location of the backup sets to restore, click one of the following options:

   • From previous backups of database

     Select the database to restore from the drop-down list. The list contains only databases that have been backed up according to the msdb backup history.

   • From file or tape

     Click the browse (...) button to open the Select backup devices dialog box. In the Backup media type box, select one of the listed device types. To select one or more devices for the Backup media box, click Add.

     After you add the devices you want to the Backup media list box, click OK to return to the General page.

6. In the Select the transaction log backups to restore grid, select the backups to restore. This grid lists the transaction log backups available for the selected database. A log backup is available only if its First LSN greater than the Last LSN of the database. Log backups are listed in the order of the log sequence numbers (LSN) they contain, and they must be restored in this order.

   The following table lists the column headers of the grid and describes their values.

   Header	Value
   Restore	Selected check boxes indicate the backup sets to be restored.
   Name	Name of the backup set.
   Component	Backed-up component: Database, File, or <blank> (for transaction logs).
   Database	Name of the database involved in the backup operation.
   Start Date	Date and time when the backup operation began, presented in the regional setting of the client.
   Finish Date	Date and time when the backup operation finished, presented in the regional setting of the client.
   First LSN	Log sequence number of the first transaction in the backup set. Blank for file backups.
   Last LSN	Log sequence number of the last transaction in the backup set. Blank for file backups.
   Checkpoint LSN	Log sequence number of the most recent checkpoint at the time the backup was created.
   Full LSN	Log sequence number of the most recent full database backup.
   Server	Name of the Database Engine instance that performed the backup operation.
   User Name	Name of the user who performed the backup operation.
   Size	Size of the backup set in bytes.
   Position	Position of the backup set in the volume.
   Expiration	Date and time the backup set expires.

7. Select one of the following:

   • Point in time

     Either retain the default (Most recent possible) or select a specific date and time by clicking the browse button, which opens the Point in Time Restore dialog box.

   • Marked transaction

     Restore the database to a previously marked transaction. Selecting this option launches the Select Marked Transaction dialog box, which displays a grid listing the marked transactions available in the selected transaction log backups.

     By default, the restore is up to, but excluding, the marked transaction. To restore the marked transaction also, select Include marked transaction.

     The following table lists the column headers of the grid and describes their values.

     Header	Value
     <blank>	Displays a checkbox for selecting the mark.
     Transaction Mark	Name of the marked transaction specified by the user when the transaction was committed.
     Date	Date and time of the transaction when it was committed. Transaction date and time are displayed as recorded in the msdb gmarkhistory table, not in the client computer's date and time.
     Description	Description of marked transaction specified by the user when the transaction was committed (if any).
     LSN	Log sequence number of the marked transaction.
     Database	Name of the database where the marked transaction was committed.
     User Name	Name of the database user who committed the marked transaction.

8. To view or select the advanced options, click Options in the Select a page pane.

9. In the Restore options section, the choices are:

   • Preserve the replication settings (WITH KEEP_REPLICATION)

     Preserves the replication settings when restoring a published database to a server other than the server where the database was created.

     This option is available only with the Leave the database ready for use by rolling back the uncommitted transactions... option (described later), which is equivalent to restoring a backup with the RECOVERY option.

     Checking this option is equivalent to using the KEEP_REPLICATION option in a Transact-SQL RESTORE statement.

   • Prompt before restoring each backup

     Before restoring each backup set (after the first), this option brings up the Continue with Restore dialog box, which asks you to indicate whether you want to continue the restore sequence. This dialog displays the name of the next media set (if available), the backup set name, and backup set description.

     This option is particularly useful when you must swap tapes for different media sets. For example, you can use it when the server has only one tape device. Wait until you are ready to proceed before clicking OK.

     Clicking No leaves the database in the restoring state. At your convenience, you can continue the restore sequence after the last restore that completed. If the next backup is a data or differential backup, use the Restore Database task again. If the next backup is a log backup, use the Restore Transaction Log task.

   • Restrict access to the restored database (WITH RESTRICTED_USER)

     Makes the restored database available only to the members of db_owner, dbcreator, or sysadmin.

     Checking this option is synonymous to using the RESTRICTED_USER option in a Transact-SQL RESTORE statement.

10. For the Recovery state options, specify the state of the database after the restore operation.

    • Leave the database ready for use by rolling back uncommitted transactions. Additional transaction logs cannot be restored. (RESTORE WITH RECOVERY)

      Recovers the database. This option is equivalent to the RECOVERY option in a Transact-SQL RESTORE statement.

      Choose this option only if you have no log files you want to restore.

    • Leave the database non-operational, and do not roll back uncommitted transactions. Additional transaction logs can be restored. (RESTORE WITH NORECOVERY)

      Leaves the database unrecovered, in the RESTORING state. This option is equivalent to using the NORECOVERY option in a Transact-SQL RESTORE statement.

      When you choose this option, the Preserve replication settings option is unavailable.

      Ważne:
      For a mirror or secondary database, always select this option.

    • Leave the database in read-only mode. Undo uncommitted transactions, but save the undo actions in a file so that recovery effects can be reversed. (RESTORE WITH STANDBY)

      Leaves the database in a standby state. This option is equivalent to using the STANDBY option in a Transact-SQL RESTORE statement.

      Choosing this option requires that you specify a standby file.

11. Optionally, specify a standby file name in the Standby file text box. This option is required if you leave the database in read-only mode. You can browse for the standby file or type its pathname in the text box.

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Using Transact-SQL

Ważne:
We recommend that you always explicitly specify either WITH NORECOVERY or WITH RECOVERY in every RESTORE statement to eliminate ambiguity. This is particularly important when writing scripts.

To restore a transaction log backup

1. Execute the RESTORE LOG statement to apply the transaction log backup, specifying:

   • The name of the database to which the transaction log will be applied.

   • The backup device where the transaction log backup will be restored from.

   • The NORECOVERY clause.

   The basic syntax for this statement is as follows:

   RESTORE LOG database_name FROM <backup_device> WITH NORECOVERY.

   Where database_name is the name of database and <backup_device>is the name of the device that contains the log backup being restored.

2. Repeat step 1 for each transaction log backup you have to apply.

3. After restoring the last backup in your restore sequence, to recover the database use one of the following statements:

   • Recover the database as part of the last RESTORE LOG statement:

     RESTORE LOG <database_name> FROM <backup_device> WITH RECOVERY;
     GO
     

   • Wait to recover the database by using a separate RESTORE DATABASE statement:

     RESTORE LOG <database_name> FROM <backup_device> WITH NORECOVERY; 
     RESTORE DATABASE <database_name> WITH RECOVERY;
     GO
     

     Waiting to recover the database gives you the opportunity to verify that you have restored all of the necessary log backups. This approach is often advisable when you are performing a point-in-time restore.

   Ważne:
   If you are creating a mirror database, omit the recovery step. A mirror database must remain in the RESTORING state.

Examples (Transact-SQL)

By default, the AdventureWorks2012 database uses the simple recovery model. The following examples require modifying the database to use the full recovery model, as follows:

ALTER DATABASE AdventureWorks2012 SET RECOVERY FULL;

A. Applying a single transaction log backup

The following example starts by restoring the AdventureWorks2012 database by using a full database backup that resides on a backup device named AdventureWorks2012_1. The example then applies the first transaction log backup that resides on a backup device named AdventureWorks2012_log. Finally, the example recovers the database.

RESTORE DATABASE AdventureWorks2012
   FROM AdventureWorks2012_1
   WITH NORECOVERY;
GO
RESTORE LOG AdventureWorks2012
   FROM AdventureWorks2012_log
   WITH FILE = 1,
   WITH NORECOVERY;
GO
RESTORE DATABASE AdventureWorks2012
   WITH RECOVERY;
GO

B. Applying multiple transaction log backups

The following example starts by restoring the AdventureWorks2012 database by using a full database backup that resides on a backup device named AdventureWorks2012_1. The example then applies, one by one, the first three transaction log backups that reside on a backup device named AdventureWorks2012_log. Finally, the example recovers the database.

RESTORE DATABASE AdventureWorks2012
   FROM AdventureWorks2012_1
   WITH NORECOVERY;
GO
RESTORE LOG AdventureWorks2012
   FROM AdventureWorks2012_log
   WITH FILE = 1,
   NORECOVERY;
GO
RESTORE LOG AdventureWorks2012
   FROM AdventureWorks2012_log
   WITH FILE = 2,
   WITH NORECOVERY;
GO
RESTORE LOG AdventureWorks2012
   FROM AdventureWorks2012_log
   WITH FILE = 3,
   WITH NORECOVERY;
GO
RESTORE DATABASE AdventureWorks2012
   WITH RECOVERY;
GO

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Related Tasks

• Back Up a Transaction Log (SQL Server)

• Restore a Database Backup (SQL Server Management Studio)

• Restore a Database to the Point of Failure Under the Full Recovery Model (Transact-SQL)

• Restore a SQL Server Database to a Point in Time (Full Recovery Model)

• Restore a Database to a Marked Transaction (SQL Server Management Studio)

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Zobacz także

Odwołanie

RESTORE (Transact-SQL)

Koncepcje

Apply Transaction Log Backups (SQL Server)