Resource database:-
The 5th system database in SQL Server is the resource database. This database is hidden from users and is read-only.
Resource databases, which are used to offer a collection of system objects that are consistent across all editions of SQL Server, were first introduced with SQL Server 2005.
Here are some important points about it:
Purpose: The read-only Resource database serves as a storage space for the system objects and metadata that the SQL Server instance needs. It keeps track of system objects like functions, stored procedures, and system catalog views.
Hidden Database: Resource databases are concealed and not immediately accessible by users or administrators, in contrast to user databases. The SQL Server engine is intended to be used internally.
Single Instance: Each SQL Server instance only has one Resource database, which is shared by all the databases that are hosted by that instance.
Patches and Upgrades: The Resource database is modified to update system objects during the installation of a service pack or a SQL Server upgrade. This aids in maintaining compatibility between the installed version and the system catalog.
Version-specific: The Resource database only supports that particular version. A new Resource database is built to correspond with the system objects of the new version whenever an SQL Server instance is updated.
Recovery Model: Because the Resource database is designed to be read-only and does not require transaction log backups, it employs the Simple recovery model.
Security: The Resource database includes stringent security controls since it is necessary for the SQL Server instance to run. It is only accessible to the SQL Server service account and highly privileged administrators.
Avoid Modifications: Playing around with the Resource database might cause serious problems and possibly ruin the database. Any direct modifications to this database must be avoided.
System Object Access: When resolving system object references in queries, the SQL Server engine checks the Resource database. It aids in effectively retrieving data about system items.
File Location: The Resource database files (MDF and LDF) are kept in the 'MSSQLBinn' folder of the SQL Server installation directory.
By default, the location of resource database files are <drive>:\Program Files\Microsoft SQL Server\MSSQL1.<instance_name>\Binn\
The resource database's ID is 32767.
The T-SQL command cannot be used to back up and restore this database.
Components of the
Resource Database:
The Resource database contains several components, including system tables, system views, system stored procedures, and system functions.
A few Important components of the Resource database are given
below:
System Tables: This
database contains system tables that store metadata about system objects: stored
procedures, views, and functions. A few of them are sys.all_columns,
sys.all_objects, and sys.all_parameters.
System Views: This
database also contains system views which provide easy access to system tables.
A few critical views of this database are sys.all_columns, sys.all_objects, and
sys.all_parameters.
System Stored
Procedures: The resource database also has a few system-stored procedures that help DBA to perform their administrative tasks easily. For example: sp_help,
sp_helptext, and sp_columns.
System Functions:
System functions provide more details about system objects & database
settings. A few of them are DATABASEPROPERTYEX and OBJECTPROPERTYEX.
Functions of the
Resource Database:
Provide a unified set of system objects across all editions of
SQL Server. A few essential functions of the Resource database are given below:
Providing Consistent
System Objects
Supporting Upgrades
Enforcing Object
Consistency
Providing Information
Conclusion:
This database is used to support upgrades and enforce object
consistency.
Also, provide details of system objects and database
settings.
This database is essential for managing and administering
SQL Server instances effectively.
Resource database is a read-only database.
Should not modify or delete any objects from this database.
FAQ:-
Q1. How do I identify
the location of a resource database in SQL Server?
Ans. Using the below query, we can get the Resource database
location & details.
USE master
GO
SELECT 'ResourceDB' AS 'DBName', NAME AS [DBFileType], FILENAME AS
[ResourceDBFileLocation]
FROM sys.sysaltfiles WHERE DBID = 32767
Q2. What is a resource
database in SQL Server?
Ans. The resource database is the 5th system
database. This database is read-only and hidden from the users. Also, provide a set of system objects
that are consistent across all editions of SQL Server.
Q3. What is the use
of resource databases in SQL Server?
Ans. This database is used to support upgrades, and enforce
object consistency.
Q4. Why resource database
is hidden in SQL Server?
Ans. Resource database physically contains all system
objects that are available in sys. schema in each database, are physically
located in the resource database
Q5. How to know the SQL server
resource database location?
Ans. We can use a T-SQL query to fetch the location of the Resource database. Refer to Q1 for a query.
Q6. How to take a backup of the resource database in an SQL server?
Ans. We can't take a backup of the resource database using the BACKUP
T-SQL statement. But we can take the backup using a different way. Just stop the
SQL service, copy the physical files (mssqlsystemresource. mdf and
mssqlsystemresource. ldf), and then start the SQL Service.
Q7. How to get a version
of the resource database?
Ans. Use the below query to get the version details of the Resource
database:
SELECT SERVERPROPERTY('ResourceVersion')
Q8. Can we take the
backup of the Resource database?
Ans. Yes, we can. But not using the TSQL command. Refer to Qns7 for
more details.
Q9. How to get the last
updated details of the Resource database?
Ans. Use the below command to get the last updated date &
time of the Resource database:
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