What to Do When SQL DBCC CHECKDB Repair Allow Data Loss Failed

admin | December 23rd, 2019 | SQL |

In this blog, we will give the complete solution when the DBCC CHECKDB Repair Allow Data Loss failed. This command is used to recover SQL database. But sometimes it does not work well due to many reasons. Here we will discuss what is DBCC command, how it fix the database corruption, when this command does not work, and the alternate solution for SQL database recovery. So let’s start with the step by step guide.

Microsoft SQL Server is the most preferred database management system nowadays. It effectively stores and retrieves data. However, when we talk about SQL Server, there is also a corruption problem. DBCC commands are used to fix the corruption problem. But these are not a successful solution to fix the corruption issue. Now users searching for an alternate solution to recover corrupt SQL database MDF file when the DBCC CHECKDB Repair Allow Data Loss not working.


The DBCC CHECKDB command is executed in SQL Server to check the logical and physical integrity of all objects in the database. These components can include pages, values, index relationships, tables, and triggers. This process involves many structural integrity checks.

If a check fails while executing the DBCC command, an error message may appear. Due to various problems, the SQL DBCC CHECKDB Repair_Allow_Data_Loss command must be executed on the database components. Some of the issues are SQL page corruption, corruption of header, sudden system shutdown or power failure, hardware issue, etc.

Before going further, let’s know what DBCC CHECKDB REPAIR_ALLOW_DATA_LOSS fixes with the help of screenshot:

DBCC CHECKDB Repair Allow Data Loss

Know What Happens When DBCC CHECKDB REPAIR ALLOW DATA LOSS is Executed?

When setting up a database in emergency mode using the ALTER DATABASE statement, the DBCC CHECKDB command performs certain types of special repairs on the database if this option REPAIR_ALLOW_DATA_LOSS is specified. These repairs allow non-recoverable databases to be brought back online in a consistent state. All repairs must be used as a last resort and only if you cannot restore the database from backup. When the entire database is placed in emergency mode, the database is marked READ_ONLY, logging is disabled, and access to members of the sysadmin fixed server role is restricted.

When the SQL database is in emergency mode and SQL DBCC CHECKDB REPAIR_ALLOW_DATA_LOSS is executed, the following steps are performed:

  • DBCC CHECKDB tries to restore SQL database by using a log-based recovery technique.
  • DBCC CHECKDB uses all pages that have been marked as inaccessible due to checksum or I/O errors when such errors cannot occur.
  • Due to the corruption of the transaction log, SQL database recovery is not possible and the transaction logs are re-created. Rebuilding the transaction log files can result in a lack or problem in transaction consistency.

What to Do When SQL DBCC CHECKDB Repair Allow Data Loss Failed?

Now the question arises here is what to do if the DBCC CHECKDB Repair Allow Data Loss not working? Is there any alternate solution to recover corrupt SQL database? Yes, in this situation you need an alternate method to repair SQL Server database files. SQL Recovery software is the best solution to fix all kinds of SQL database corruption issues. It enables you to recover SQL database without backup including all objects like tables, triggers, rules, keys, index, etc. With this tool, one can recover deleted records from the table and save the data directly to the live SQL database.

The software supports to repair corrupt MDF file of SQL Server 2019, 2017, 2016, 2014, 2012, 2008 and all previous versions. It provides an option to preview and restore selected data to the new or existing database. The application also supports ASCII and UNICODE XML datatype.

Steps to Recover Corrupt SQL Database Without DBCC CHECKDB

Here are the simple and quick steps to perform SQL Database Recovery when SQL DBCC CHECKDB Repair Allow Data Loss failed:

Step 1. Download SQL Recovery tool and install it on your system.

Download SQL Recovery Free

Step 2. Click “Open” and select the corrupt SQL database file.

SQL Recovery

Step 3. Under Scan Options, select the “Quick” or “Advance” scan. After check the “Auto-detect SQL file MDF version” box.

Repair Corrupt MDF File

If you want to preview and recover deleted records from the table, select “Preview Deleted Records”.

Step 4. After completion of the scanning process, the software will display the preview of recovered SQL database objects.

Recover SQL Database Files

Step 5. Export data to the “Live SQL Server Database” and enter your SQL account login credentials.

Restore SQL Database

Step 6. Restore data to a “new database” or an “existing database” as per your needs.

Restore SQL Database to New Database

Step 7. Choose Export data “With Only Schema” or “with Schema & Data” both.

Recover Corrupt SQL Database Files

Step 8. Now, click the Export button and the software will successfully restore SQL database in just a few minutes.

Recover SQL Database MDF File


In the discussed blog above, we provided complete information on DBCC CHECKDB and the alternative of Repair Allow Data Loss. We also discussed the reasons behind DBCC CHECKDB Repair Allow Data Loss failed. The suggested alternate solution helps to recover SQL database from all types of corruption.