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RESTORE HEADERONLY (Transact-SQL)

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

Note

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

Topic link iconTransact-SQL Syntax Conventions

Syntax

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:

Note

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.

Note

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

Description for other backup sets

BackupName

nvarchar(128)

Backup set name.

Data set name

BackupDescription

nvarchar(255)

Backup set description.

Data set description

BackupType

smallint

Backup type:

1 = Database

2 = Transaction log

4 = File

5 = Differential database

6 = Differential file

7 = Partial

8 = Differential partial

Backup type:

1 = Normal

5 = Differential

16 = Incremental

17 = Daily

ExpirationDate

datetime

Expiration date for the backup set.

NULL

Compressed

BYTE(1)

Whether the backup set is compressed using software-based compression:

0 = No

1 = Yes

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).

Position of the backup set in the volume

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).

NULL

UserName

nvarchar(128)

User name that performed the backup operation.

User name that performed the backup operation

ServerName

nvarchar(128)

Name of the server that wrote the backup set.

NULL

DatabaseName

nvarchar(128)

Name of the database that was backed up.

NULL

DatabaseVersion

int

Version of the database from which the backup was created.

NULL

DatabaseCreationDate

datetime

Date and time the database was created.

NULL

BackupSize

numeric(20,0)

Size of the backup, in bytes.

NULL

FirstLSN

numeric(25,0)

Log sequence number of the first log record in the backup set.

NULL

LastLSN

numeric(25,0)

Log sequence number of the next log record after the backup set.

NULL

CheckpointLSN

numeric(25,0)

Log sequence number of the most recent checkpoint at the time the backup was created.

NULL

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.

NULL

BackupStartDate

datetime

Date and time that the backup operation began.

Media Write Date

BackupFinishDate

datetime

Date and time that the backup operation finished.

Media Write Date

SortOrder

smallint

Server sort order. This column is valid for database backups only. Provided for backward compatibility.

NULL

CodePage

smallint

Server code page or character set used by the server.

NULL

UnicodeLocaleId

int

Server Unicode locale ID configuration option used for Unicode character data sorting. Provided for backward compatibility.

NULL

UnicodeComparisonStyle

int

Server Unicode comparison style configuration option, which provides additional control over the sorting of Unicode data. Provided for backward compatibility.

NULL

CompatibilityLevel

tinyint

Compatibility level setting of the database from which the backup was created.

NULL

SoftwareVendorId

int

Software vendor identification number. For SQL Server, this number is 4608 (or hexadecimal 0x1200).

Software vendor identification number

SoftwareVersionMajor

int

Major version number of the server that created the backup set.

Major version number of the software that created the backup set

SoftwareVersionMinor

int

Minor version number of the server that created the backup set.

Minor version number of the software that created the backup set

SoftwareVersionBuild

int

Build number of the server that created the backup set.

NULL

MachineName

nvarchar(128)

Name of the computer that performed the backup operation.

Type 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.

Important noteImportant
We recommend that instead of Flags you use the individual Boolean columns (listed below starting with HasBulkLoggedData and ending with IsCopyOnly).

NULL

BindingID

uniqueidentifier

Binding ID for the database. This corresponds to sys.database_recovery_statusdatabase_guid. When a database is restored, a new value is assigned. Also see FamilyGUID (below).

NULL

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.

NULL

Collation

nvarchar(128)

Collation used by the database.

NULL

FamilyGUID

uniqueidentifier

ID of the original database when created. This value stays the same when the database is restored.

NULL

HasBulkLoggedData

bit

1 = Log backup containing bulk-logged operations.

NULL

IsSnapshot

bit

1 = Snapshot backup.

NULL

IsReadOnly

bit

1 = Database was read-only when backed up.

NULL

IsSingleUser

bit

1 = Database was single-user when backed up.

NULL

HasBackupChecksums

bit

1 = Backup contains backup checksums.

NULL

IsDamaged

bit

1 = Database was damaged when backed up, but the backup operation was requested to continue despite errors.

NULL

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.

NULL

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.

NULL

IsForceOffline

bit

1 = Backup taken with NORECOVERY; the database was taken offline by backup.

NULL

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.

NULL

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.

NULL

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.

NULL

RecoveryModel

nvarchar(60)

Recovery model for the Database, one of:

FULL

BULK-LOGGED

SIMPLE

NULL

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 Base of a Differential Backup.

NULL

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.

NULL

BackupTypeDescription

nvarchar(60)

Backup type as string, one of:

DATABASE

TRANSACTION LOG

FILE OR FILEGROUP

DATABASE DIFFERENTIAL

FILE DIFFERENTIAL PARTIAL

PARTIAL DIFFERENTIAL

Backup type as string, one of:

NORMAL

DIFFERENTIAL

INCREMENTAL

DAILY

BackupSetGUID

uniqueidentifier NULL

Unique identification number of the backup set, by which it is identified on the media.

NULL

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.

NULL

Note

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.

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.

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).

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.

Security noteSecurity Note

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.

Examples

The following example returns the information in the header for the disk file C:\AdventureWorks2008R2-FullBackup.bak.

RESTORE HEADERONLY 
FROM DISK = N'C:\AdventureWorks2008R2-FullBackup.bak' 
WITH NOUNLOAD;
GO