sys.master_files (Transact-SQL)

THIS TOPIC APPLIES TO:yesSQL Server (starting with 2008)noAzure SQL DatabasenoAzure SQL Data Warehouse yesParallel Data Warehouse

Contains a row per file of a database as stored in the master database. This is a single, system-wide view.

Column name Data type Description
database_id int ID of the database to which this file applies. The masterdatabase_id is always 1.
file_id int ID of the file within database. The primary file_id is always 1.
file_guid uniqueidentifier Unique identifier of the file.

NULL = Database was upgraded from an earlier version of SQL Server.
type tinyint File type:

0 = Rows.

1 = Log

2 = FILESTREAM

3 = Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.

4 = Full-text (Full-text catalogs earlier than SQL Server 2008; full-text catalogs that are upgraded to or created in SQL Server 2008 or higher will report a file type 0.)
type_desc nvarchar(60) Description of the file type:

ROWS

LOG

FILESTREAM

FULLTEXT (Full-text catalogs earlier than SQL Server 2008.)
data_space_id int ID of the data space to which this file belongs. Data space is a filegroup.

0 = Log files
name sysname Logical name of the file in the database.
physical_name nvarchar(260) Operating-system file name.
state tinyint File state:

0 = ONLINE

1 = RESTORING

2 = RECOVERING

3 = RECOVERY_PENDING

4 = SUSPECT

5 = Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.

6 = OFFLINE

7 = DEFUNCT
state_desc nvarchar(60) Description of the file state:

ONLINE

RESTORING

RECOVERING

RECOVERY_PENDING

SUSPECT

OFFLINE

DEFUNCT

For more information, see File States.
size int Current file size, in 8-KB pages. For a database snapshot, size reflects the maximum space that the snapshot can ever use for the file.

Note: This field is populated as zero for FILESTREAM containers. Query the sys.database_files catalog view for the actual size of FILESTREAM containers.
max_size int Maximum file size, in 8-KB pages:

0 = No growth is allowed.

-1 = File will grow until the disk is full.

268435456 = Log file will grow to a maximum size of 2 TB.

Note: Databases that are upgraded with an unlimited log file size will report -1 for the maximum size of the log file.
growth int 0 = File is fixed size and will not grow.

>0 = File will grow automatically.

If is_percent_growth = 0, growth increment is in units of 8-KB pages, rounded to the nearest 64 KB

If is_percent_growth = 1, growth increment is expressed as a whole number percentage.
is_media_read_onlyF bit 1 = File is on read-only media.

0 = File is on read/write media.
is_read_only bit 1 = File is marked read-only.

0 = file is marked read/write.
is_sparse bit 1 = File is a sparse file.

0 = File is not a sparse file.

For more information, see View the Size of the Sparse File of a Database Snapshot (Transact-SQL).
is_percent_growth bit 1 = Growth of the file is a percentage.

0 = Absolute growth size in pages.
is_name_reserved bit 1 = Dropped file name is reusable. A log backup must be taken before the name (name or physical_name) can be reused for a new file name.

0 = File name is unavailable for reuse.
create_lsn numeric(25,0) Log sequence number (LSN) at which the file was created.
drop_lsn numeric(25,0) LSN at which the file was dropped.
read_only_lsn numeric(25,0) LSN at which the filegroup that contains the file changed from read/write to read-only (most recent change).
read_write_lsn numeric(25,0) LSN at which the filegroup that contains the file changed from read-only to read/write (most recent change).
differential_base_lsn numeric(25,0) Base for differential backups. Data extents changed after this LSN will be included in a differential backup.
differential_base_guid uniqueidentifier Unique identifier of the base backup on which a differential backup will be based.
differential_base_time datetime Time corresponding to differential_base_lsn.
redo_start_lsn numeric(25,0) LSN at which the next roll forward must start.

Is NULL unless state = RESTORING or state = RECOVERY_PENDING.
redo_start_fork_guid uniqueidentifier Unique identifier of the recovery fork. The first_fork_guid of the next log backup restored must match this value. This represents the current state of the container.
redo_target_lsn numeric(25,0) LSN at which the online roll forward on this file can stop.

Is NULL unless state = RESTORING or state = RECOVERY_PENDING.
redo_target_fork_guid uniqueidentifier The recovery fork on which the container can be recovered. Paired with redo_target_lsn.
backup_lsn numeric(25,0) The LSN of the most recent data or differential backup of the file.
credential_id int The credential_id from sys.credentials used for storing the file. For example, when SQL Server is running on an Azure Virtual Machine and the database files are stored in Azure blob storage, a credential is configured with the access credentials to the storage location.
Note

When you drop or rebuild large indexes, or drop or truncate large tables, the Database Engine defers the actual page deallocations, and their associated locks, until after the transaction commits. Deferred drop operations do not release allocated space immediately. Therefore, the values returned by sys.master_files immediately after dropping or truncating a large object may not reflect the actual disk space available.

Permissions

The minimum permissions that are required to see the corresponding row are CREATE DATABASE, ALTER ANY DATABASE, or VIEW ANY DEFINITION.

See Also

Databases and Files Catalog Views (Transact-SQL)
File States
sys.databases (Transact-SQL)
sys.database_files (Transact-SQL)
Database Files and Filegroups