The MDF is known as the primary database file of the MS SQL Server. The MDF file stores all the data items of the MS SQL Server such as Views, XML Indexes, triggers, Tables, and other Stored Procedures. The MDF file is also known as the master database file of the MS SQL Server. Each SQL Server database will contain at least an MDF file. Without the master database, the MS SQL Server will become inaccessible. 

Keep in mind that the MDF file or the master database can be considered the most important element of the MS SQL Server database. This is why you need to pay close attention to the master database to prevent it from corruption. 

Several reasons will make the MS SQL Server master database face corruption. When this takes place, users won’t get to access the MS SQL Server. If you don’t fix this issue in time, you will face severe data loss. 

Causes of MDF File Corruption

Even though the MS SQL Server master database isn’t vulnerable to corruption, some specific things will make the MS SQL Server corrupt. The primary goal of discussing the reasons for MDF file corruption is to let you understand whether the MDF file is corrupted or not. Here are the most common causes you need to remember:

• Improper shutdown of the systems of sudden power failure will undoubtedly affect the master database. As per Thetns Group, improper shutdown can also lead to data loss. 
• A faulty operating system can affect the configuration of the MDF file 
• Bugs in the server are super dangerous 
• Virus outbreak as well as hardware issues such as hard disk failure is one of the most common causes of MDF file corruption 
• Unexpected shutdown of the system 
• Corruption of the external storage 

How Can You Repair the MDF File?

MS SQL Server comes with in-built Database Console Command known as DBCC CHECKDB. The primary objective of this console is to test both the logical as well as physical integrity of the database objects. Here are the following operations that you need to check:

• Run the DBCC CHECKALLOC command in the database 
• Run the DBCC CHECK CATALOG command in the database 
• Run the DBCC CHECKTABLE command on each table and view the database 
• Authenticate the content as per the indexed view of the database 

Remember that DBCC CHECKDB is capable of checking the consistency of the database pages as well as other structure checks. After that, it will report the errors, if the system finds anything. 

When the DBCC CHECKDB reports the different types of database consistency errors, make sure you restore the database from a proper backup option. However, if you have an old backup or don’t have anything at all, the CHECKDB will provide numerous options to fix the corrupted MDF file of the MS SQL Server. 

The different repair options you need to remember are:

• REPAIR_FAST: This will help you maintain the syntax as per the backward compatibility. It won’t help you perform any type of repair function. Here is the syntax you need to remember: 

DBCC CHECKDB (‘DB NAME’, REPAIR-FAST)

• REPAIR_REBUILD: This is probably one of the most effective repair options you need to consider. This option will execute different types of repair procedures that don’t contain any type of data loss. This will perform quick repairs and other time-consuming repairs too. The syntax is:

DBCC CHECKDB (‘DB Name’, REPAIR_REBUILD)

• REPAIR_ALLOW_DATA_LOSS: MS developers ask their users to use this repair option as the last resort to fix the errors or corruption. This is because even if the repair options are reallocating, it might end up affecting the data items permanently. The syntax is: 

DBCC CHECKDB (‘DB Name’, REPAIR_ALLOW_DATA_LOSS)

The Essential Things You Should Think about When Using DBCC CHECKDB Repair Options 

When you’re planning to use the DBCC CHECKDB repair options to address the corrupted master database, make sure you pay close attention to the requirements below:

• The primary and most important prerequisite is that you need to ensure your SQL server runs on a particular database in a single-user mode. When you don’t set the database as per the single-user mode, you might encounter an error message “Repair Statement is not processed. The database needs to be in Single-user mode”. 

Consider running the MS SQL Server database in the single-user mode so that you can prevent yourself from facing such problems. You also need to use the syntaxes associated with DBCC CHECKDB properly so that you can run the command prompt without any issues. This is one of the best ways to maintain the health of your MS SQL Server master database. 

What to Do When the DBCC CHECKDB Fails to Work?

If you think that the DBCC CHECKDB tool is not effective at addressing the corrupted master database, make sure you choose the best SQL recovery tool to quickly recover all types of MS SQL Server database errors. The software will also help you prevent data loss. 

Conclusion 

Now that you know the process of corrupted MDF files of the MS SQL server database, you won’t face any problems. Make sure you contact us if you have any more questions.