RESTORE HEADERONLY (Transact-SQL)

Returns a result set containing all the backup header information for all backup sets on a particular backup device.

[!UWAGA]

For the descriptions of the arguments, see RESTORE Arguments (Transact-SQL).

Transact-SQL Syntax Conventions

Składnia

RESTORE HEADERONLY 
FROM <backup_device> 
[ WITH 
 {
--Backup Set Options
   FILE = { backup_set_file_number | @backup_set_file_number } 
 | PASSWORD = { password | @password_variable } 

--Media Set Options
 | MEDIANAME = { media_name | @media_name_variable } 
 | MEDIAPASSWORD = { mediapassword | @mediapassword_variable }

--Error Management Options
 | { CHECKSUM | NO_CHECKSUM } 
 | { STOP_ON_ERROR | CONTINUE_AFTER_ERROR }

--Tape Options
 | { REWIND | NOREWIND } 
 | { UNLOAD | NOUNLOAD }  
 } [ ,...n ]
]
[;]

<backup_device> ::=
{ 
   { logical_backup_device_name |
      @logical_backup_device_name_var }
   | { DISK | TAPE } = { 'physical_backup_device_name' |
       @physical_backup_device_name_var } 
} 

Arguments

For descriptions of the RESTORE HEADERONLY arguments, see RESTORE Arguments (Transact-SQL).

Result Sets

For each backup on a given device, the server sends a row of header information with the following columns:

[!UWAGA]

RESTORE HEADERONLY looks at all backup sets on the media. Therefore, producing this result set when using high-capacity tape drives can take some time. To get a quick look at the media without getting information about every backup set, use RESTORE LABELONLY or specify FILE = backup_set_file_number.

[!UWAGA]

Due to the nature of Microsoft Tape Format, it is possible for backup sets from other software programs to occupy space on the same media as Microsoft SQL Server backup sets. The result set returned by RESTORE HEADERONLY includes a row for each of these other backup sets.

Column name	Data type	Description for SQL Server backup sets
BackupName	nvarchar(128)	Backup set name.
BackupDescription	nvarchar(255)	Backup set description.
BackupType	smallint	Backup type: 1 = Database 2 = Transaction log 4 = File 5 = Differential database 6 = Differential file 7 = Partial 8 = Differential partial
ExpirationDate	datetime	Expiration date for the backup set.
Compressed	BYTE(1)	Whether the backup set is compressed using software-based compression: 0 = No 1 = Yes
Position	smallint	Position of the backup set in the volume (for use with the FILE = option).
DeviceType	tinyint	Number corresponding to the device used for the backup operation. Disk: 2 = Logical 102 = Physical Tape: 5 = Logical 105 = Physical Virtual Device: 7 = Logical 107 = Physical Logical device names and device numbers are in sys.backup_devices; for more information, see sys.backup_devices (Transact-SQL).
UserName	nvarchar(128)	User name that performed the backup operation.
ServerName	nvarchar(128)	Name of the server that wrote the backup set.
DatabaseName	nvarchar(128)	Name of the database that was backed up.
DatabaseVersion	int	Version of the database from which the backup was created.
DatabaseCreationDate	datetime	Date and time the database was created.
BackupSize	numeric(20,0)	Size of the backup, in bytes.
FirstLSN	numeric(25,0)	Log sequence number of the first log record in the backup set.
LastLSN	numeric(25,0)	Log sequence number of the next log record after the backup set.
CheckpointLSN	numeric(25,0)	Log sequence number of the most recent checkpoint at the time the backup was created.
DatabaseBackupLSN	numeric(25,0)	Log sequence number of the most recent full database backup. DatabaseBackupLSN is the “begin of checkpoint” that is triggered when the backup starts. This LSN will coincide with FirstLSN if the backup is taken when the database is idle and no replication is configured.
BackupStartDate	datetime	Date and time that the backup operation began.
BackupFinishDate	datetime	Date and time that the backup operation finished.
SortOrder	smallint	Server sort order. This column is valid for database backups only. Provided for backward compatibility.
CodePage	smallint	Server code page or character set used by the server.
UnicodeLocaleId	int	Server Unicode locale ID configuration option used for Unicode character data sorting. Provided for backward compatibility.
UnicodeComparisonStyle	int	Server Unicode comparison style configuration option, which provides additional control over the sorting of Unicode data. Provided for backward compatibility.
CompatibilityLevel	tinyint	Compatibility level setting of the database from which the backup was created.
SoftwareVendorId	int	Software vendor identification number. For SQL Server, this number is 4608 (or hexadecimal 0x1200).
SoftwareVersionMajor	int	Major version number of the server that created the backup set.
SoftwareVersionMinor	int	Minor version number of the server that created the backup set.
SoftwareVersionBuild	int	Build number of the server that created the backup set.
MachineName	nvarchar(128)	Name of the computer that performed the backup operation.
Flags	int	Individual flags bit meanings if set to 1: 1 = Log backup contains bulk-logged operations. 2 = Snapshot backup. 4 = Database was read-only when backed up. 8 = Database was in single-user mode when backed up. 16 = Backup contains backup checksums. 32 = Database was damaged when backed up, but the backup operation was requested to continue despite errors. 64 = Tail log backup. 128 = Tail log backup with incomplete metadata. 256 = Tail log backup with NORECOVERY. Ważne: We recommend that instead of Flags you use the individual Boolean columns (listed below starting with HasBulkLoggedData and ending with IsCopyOnly).
BindingID	uniqueidentifier	Binding ID for the database. This corresponds to sys.database_recovery_status database_guid. When a database is restored, a new value is assigned. Also see FamilyGUID (below).
RecoveryForkID	uniqueidentifier	ID for the ending recovery fork. This column corresponds to last_recovery_fork_guid in the backupset table. For data backups, RecoveryForkID equals FirstRecoveryForkID.
Collation	nvarchar(128)	Collation used by the database.
FamilyGUID	uniqueidentifier	ID of the original database when created. This value stays the same when the database is restored.
HasBulkLoggedData	bit	1 = Log backup containing bulk-logged operations.
IsSnapshot	bit	1 = Snapshot backup.
IsReadOnly	bit	1 = Database was read-only when backed up.
IsSingleUser	bit	1 = Database was single-user when backed up.
HasBackupChecksums	bit	1 = Backup contains backup checksums.
IsDamaged	bit	1 = Database was damaged when backed up, but the backup operation was requested to continue despite errors.
BeginsLogChain	bit	1 = This is the first in a continuous chain of log backups. A log chain begins with the first log backup taken after the database is created or when it is switched from the Simple to the Full or Bulk-Logged Recovery Model.
HasIncompleteMetaData	bit	1 = A tail-log backup with incomplete meta-data. For information about tail-log backups with incomplete backup metadata, see Tail-Log Backups (SQL Server).
IsForceOffline	bit	1 = Backup taken with NORECOVERY; the database was taken offline by backup.
IsCopyOnly	bit	1 = A copy-only backup. A copy-only backup does not impact the overall backup and restore procedures for the database. For more information, see Copy-Only Backups (SQL Server).
FirstRecoveryForkID	uniqueidentifier	ID for the starting recovery fork. This column corresponds to first_recovery_fork_guid in the backupset table. For data backups, FirstRecoveryForkID equals RecoveryForkID.
ForkPointLSN	numeric(25,0) NULL	If FirstRecoveryForkID is not equal to RecoveryForkID, this is the log sequence number of the fork point. Otherwise, this value is NULL.
RecoveryModel	nvarchar(60)	Recovery model for the Database, one of: FULL BULK-LOGGED SIMPLE
DifferentialBaseLSN	numeric(25,0) NULL	For a single-based differential backup, the value equals the FirstLSN of the differential base; changes with LSNs greater than or equal to DifferentialBaseLSN are included in the differential. For a multi-based differential, the value is NULL, and the base LSN must be determined at the file level. For more information, see RESTORE FILELISTONLY (Transact-SQL). For non-differential backup types, the value is always NULL. For more information, see Differential Backups (SQL Server).
DifferentialBaseGUID	uniqueidentifier	For a single-based differential backup, the value is the unique identifier of the differential base. For multi-based differentials, the value is NULL, and the differential base must be determined per file. For non-differential backup types, the value is NULL.
BackupTypeDescription	nvarchar(60)	Backup type as string, one of: DATABASE TRANSACTION LOG FILE OR FILEGROUP DATABASE DIFFERENTIAL FILE DIFFERENTIAL PARTIAL PARTIAL DIFFERENTIAL
BackupSetGUID	uniqueidentifier NULL	Unique identification number of the backup set, by which it is identified on the media.
CompressedBackupSize	bigint	Byte count of the backup set. For uncompressed backups, this value is the same as BackupSize. To calculate the compression ratio, use CompressedBackupSize and BackupSize. During an msdb upgrade, this value is set to match the value of the BackupSize column.
containment	tinyint not NULL	Indicates the containment status of the database. 0 = database containment is off 1 = database is in partial containment

[!UWAGA]

If passwords are defined for the backup sets, RESTORE HEADERONLY shows complete information for only the backup set whose password matches the specified PASSWORD option of the command. RESTORE HEADERONLY also shows complete information for unprotected backup sets. The BackupName column for the other password-protected backup sets on the media is set to '***Password Protected***', and all other columns are NULL.

General Remarks

A client can use RESTORE HEADERONLY to retrieve all the backup header information for all backups on a particular backup device. For each backup on the backup device, the server sends the header information as a row.

Security

A backup operation may optionally specify passwords for a media set, a backup set, or both. When a password has been defined on a media set or backup set, you must specify the correct password or passwords in the RESTORE statement. These passwords prevent unauthorized restore operations and unauthorized appends of backup sets to media using Microsoft SQL Server tools. However, a password does not prevent overwrite of media using the BACKUP statement's FORMAT option.

Uwaga dotycząca zabezpieczeń

The protection provided by this password is weak. It is intended to prevent an incorrect restore using SQL Server tools by authorized or unauthorized users. It does not prevent the reading of the backup data by other means or the replacement of the password. This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. The best practice for protecting backups is to store backup tapes in a secure location or back up to disk files that are protected by adequate access control lists (ACLs). The ACLs should be set on the directory root under which backups are created.

Permissions

Beginning in SQL Server 2008, obtaining information about a backup set or backup device requires CREATE DATABASE permission. For more information, see GRANT Database Permissions (Transact-SQL).

Examples

The following example returns the information in the header for the disk file C:\AdventureWorks-FullBackup.bak.

RESTORE HEADERONLY 
FROM DISK = N'C:\AdventureWorks-FullBackup.bak' 
WITH NOUNLOAD;
GO

Zobacz także

Odwołanie

BACKUP (Transact-SQL)

backupset (Transact-SQL)

RESTORE REWINDONLY (Transact-SQL)

RESTORE VERIFYONLY (Transact-SQL)

RESTORE (Transact-SQL)

Koncepcje

Backup History and Header Information (SQL Server)

Enable or Disable Backup Checksums During Backup or Restore (SQL Server)

Media Sets, Media Families, and Backup Sets (SQL Server)

Recovery Models (SQL Server)