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model Database

The model database is used as the template for all databases created on an instance of SQL Server. Because tempdb is created every time SQL Server is started, the model database must always exist on a SQL Server system. The entire contents of the model database, including database options, are copied to the new database. Some of the settings of model are also used for creating a new tempdb during start up, so the model database must always exist on a SQL Server system.

Newly created user databases use the same recovery model as the model database. The default is user configurable. To learn the current recovery model of the model, see View or Change the Recovery Model of a Database (SQL Server).

Ważna informacjaWażne:

If you modify the model database with user-specific template information, we recommend that you back up model. For more information, see Back Up and Restore of System Databases (SQL Server).

model Usage

When a CREATE DATABASE statement is issued, the first part of the database is created by copying in the contents of the model database. The rest of the new database is then filled with empty pages.

If you modify the model database, all databases created afterward will inherit those changes. For example, you could set permissions or database options, or add objects such as tables, functions, or stored procedures.

Physical Properties of model

The following table lists initial configuration values of the model data and log files. The sizes of these files can vary slightly for different editions of SQL Server.

File

Logical name

Physical name

File growth

Primary data

modeldev

model.mdf

Autogrow by 10 percent until the disk is full.

Log

modellog

modellog.ldf

Autogrow by 10 percent to a maximum of 2 terabytes.

To move the model database or log files, see Move System Databases.

Database Options

The following table lists the default value for each database option in the model database and whether the option can be modified. To view the current settings for these options, use the sys.databases catalog view.

Database option

Default value

Can be modified

ALLOW_SNAPSHOT_ISOLATION

OFF

Yes

ANSI_NULL_DEFAULT

OFF

Yes

ANSI_NULLS

OFF

Yes

ANSI_PADDING

OFF

Yes

ANSI_WARNINGS

OFF

Yes

ARITHABORT

OFF

Yes

AUTO_CLOSE

OFF

Yes

AUTO_CREATE_STATISTICS

ON

Yes

AUTO_SHRINK

OFF

Yes

AUTO_UPDATE_STATISTICS

ON

Yes

AUTO_UPDATE_STATISTICS_ASYNC

OFF

Yes

CHANGE_TRACKING

OFF

No

CONCAT_NULL_YIELDS_NULL

OFF

Yes

CURSOR_CLOSE_ON_COMMIT

OFF

Yes

CURSOR_DEFAULT

GLOBAL

Yes

Database Availability Options

ONLINE

MULTI_USER

READ_WRITE

No

Yes

Yes

DATE_CORRELATION_OPTIMIZATION

OFF

Yes

DB_CHAINING

OFF

No

ENCRYPTION

OFF

No

NUMERIC_ROUNDABORT

OFF

Yes

PAGE_VERIFY

CHECKSUM

Yes

PARAMETERIZATION

SIMPLE

Yes

QUOTED_IDENTIFIER

OFF

Yes

READ_COMMITTED_SNAPSHOT

OFF

Yes

RECOVERY

Depends on SQL Server edition1

Yes

RECURSIVE_TRIGGERS

OFF

Yes

Service Broker Options

DISABLE_BROKER

No

TRUSTWORTHY

OFF

No

1 To verify the current recovery model of the database, see View or Change the Recovery Model of a Database (SQL Server) or sys.databases (Transact-SQL).

For a description of these database options, see ALTER DATABASE (Transact-SQL).

Restrictions

The following operations cannot be performed on the model database:

  • Adding files or filegroups.

  • Changing collation. The default collation is the server collation.

  • Changing the database owner. model is owned by sa.

  • Dropping the database.

  • Dropping the guest user from the database.

  • Enabling change data capture.

  • Participating in database mirroring.

  • Removing the primary filegroup, primary data file, or log file.

  • Renaming the database or primary filegroup.

  • Setting the database to OFFLINE.

  • Setting the primary filegroup to READ_ONLY.

  • Creating procedures, views, or triggers using the WITH ENCRYPTION option. The encryption key is tied to the database in which the object is created. Encrypted objects created in the model database can only be used in model.

System Databases

sys.databases (Transact-SQL)

sys.master_files (Transact-SQL)

Move Database Files