Repairing corrupt or damaged SQL databases is crucial to keep businesses up and running. Nevertheless, understanding the reasons behind the corruption is essential as it can prevent your databases from falling victim to unnecessary damages.
Knowing the reason makes it easier to find the most feasible SQL recovery solution and resume working for your organization. Equally important is to learn about the best tools for repairing corrupt SQL databases.
In this post, we will discuss these tools in detail. First, let’s know about the main reasons that can lead to SQL database corruption.
Reasons behind corrupted SQL databases
Here is a roster of factors that can cause damage to SQL database:
- Abrupt system shutdown due to power failures
- Bugs in SQL databases because of syntax errors, data integrity constraints, or coding issues
- Virus or malware attack resulting in corrupted database files
- Hardware issues such as bad sectors, physical damage to devices, etc.
- Network issues, like login or connection errors
- Software issues due to obsolete or incompatible versions, or faulty database engine
- Inappropriate isolation level that can cause hurdles in SQL database repair through the DBCC CHECKDB command or SQL Server Management Studio (SSMS)
Best tools for repairing corrupt SQL databases
Fixing these database issues is imperative due to their importance in the flawless functioning of the applications in the respective organizations. Usually, database admins use tools like SQL Server Management Studio in combination with Transact-SQL commands to repair the database manually.
Alongside this, several automated tools are immensely popular due to the ease of use, proficiency, and accuracy they ensure. Stellar Repair for MS SQL is one of the best tools for repairing corrupt SQL databases in this context.
Nevertheless, before you carry out any repair task, check for any recent healthy database backup. Manual methods often fail to fix several corruptions related to database. In such circumstances, you need to restore the database from the backup.
Repair corrupt databases through SSMS
To execute this task with the help of SQL Server Management Studio, you can proceed with the below steps:
1. Set your database to EMERGENCY mode
This will allow only the read-only access to the admin. Here are the steps:
- Launch SSMS and open the New Query window
- Run the following query:
ALTER DATABASE [Database_Name] SET EMERGENCY
-- e.g. --
ALTER DATABASE [SQL_DB_RST] SET EMERGENCY
2. Analyze the database to detect errors (if any)
- Run the DBCC CHECKDB command to server this task:
DBCC CHECKDB(N'Database_Name') WITH ALL_ERRORMSGS, NO_INFOMSGS
-- e.g. --
DBCC CHECKDB (N'SQL_DB_RST') WITH ALL_ERRORMSGS, NO_INFOMSGS
The query will give a list of the resulting errors and suggest a feasible repair option
3. Select the right Repair option
You can choose from some suitable Repair Options. It is advisable to set the database in Single_User mode before performing any of the repair options. Once done, set the database again to the Multi_User option. This will prevent others from using your data until the repair task is completed.
REPAIR_FAST: Mostly used as a starting step in the database repair, if you want to make the database live as soon as possible. It focuses on minor repairs and is not suitable for intense cases of database corruption.
ALTER DATABASE [SQL_DB_RST] SET SINGLE_USER;
DBCC CHECKDB (N'SQL_DB_RST', REPAIR_FAST);
ALTER DATABASE [SQL_DB_RST] SET MULTI_USER;
REPAIR_REBUILD: The safest option, as it will not harm your database during the repair. If you do not have any database backup or wish to avoid any operation that can lead to data loss, you are good to go with this option. Here is the syntax:
ALTER DATABASE [SQL_DB_RST] SET SINGLE_USER;
DBCC CHECKDB (N'SQL_DB_RST', REPAIR_REBUILD);
ALTER DATABASE [SQL_DB_RST] SET MULTI_USER;
REPAIR_ALLOW_DATA_LOSS: Use this option if your other repair options fail to deliver the right solution. As the option itself opines, it may cause you to face data loss. It can remove damaged or corrupted data to repair database corruption.
ALTER DATABASE [SQL_DB_RST] SET SINGLE_USER;
DBCC CHECKDB (N'SQL_DB_RST', REPAIR_ALLOW_DATA_LOSS);
ALTER DATABASE [SQL_DB_RST] SET MULTI_USER;
The catch with the DBCC CHECKDB command
Here, it is crucial to know that these DBCC CHECKDB repair options may not function properly for extremely corrupted databases. Several other limitations of using this command include as below:
- DBCC CHECKDB command can deallocate database pages or rows, making their recovery impossible
- Your database may attain a logically inconsistent state because of this command
- It is a time-consuming process as you may require using this command multiple times to fix all errors associated with SQL databases.
- DBCC CHECKDB does not assure complete SQL recovery, as you may lose a part of your database permanently
To avoid these limitations, you should try other tools to remove the corruption from your database. However, several critical points are worth considering while repairing the corrupt database through another tool.
- Repair both MDF and NDF files from the start
- Repair all the objects of the database including tables, rows columns, stored procedures, views, etc.
- Recover the missing or deleted records of the database
- Cross-check the database backup to look for any possibility of viruses
- Find a better way to repair the corrupt database and recover the data. Using a SQL recovery tool will be a recommended option in this regard.
Stellar Repair for MS SQL – A widely recommended SQL recovery tool
When looking for the best tools for repairing corrupt SQL databases, Stellar Repair for MS SQL is a recommended choice. Its use becomes even more crucial in several instances, such as when:
- You struggle to deal with consistency errors related to DBCC CHECKDB
- You come across error 5173 due to corruption in the MDF file header of the SQL database
- Clustered/non-clustered indexes give missing entries and wrong query results because of corruption
Here are more features of the popular SQL recovery tool:
- The tool repairs corrupt or damaged MDF and NDF files
- It rebuilds database objects while ensuring data integrity,
- Supports parallel processing for quicker SQL database recovery
- Recovers deleted or missing database records
- Repair corrupt SQL(.BAK) files and extracts the database
- Offers numerous options to save files after SQL recovery
- Lets you preview repairable MS SQL database objects
- Offers the facility of standard and advanced scan
- Can repair the corrupt SQL database on Linux Systems
Steps to repair corrupt database by using Stellar Repair for MS SQL
Here are the easy steps:
- Download and install the SQL recovery software
- Click the Browse or Find Option to select the corrupt MDF file
- Next, click Repair and select Scan or Advanced scan
- Click OK to start the process for database repair
- Preview the repairable database components
- In the File menu, click Save
- Save the database you just repaired in a selected format
- You may also select Live Database or New Database to save it
- Connect to the server by providing the necessary details.
- Choose a suitable mode to save the file and click Next
- The software will start working and saving the chosen files.
- It will show the status of the file, whether Completed, Pending, Processing, or Aborted
- Once the saving process completes, you can see the acknowledgment message
This entire process will repair and rebuild your corrupt SQL database and save it at an appropriate location. You may buy its free trial version if you just want to scan and preview the recoverable SQL server database objects.
To use the full functionality of Stellar Repair for MS SQL tool, you can buy any of the Corporate, Technician, or Toolkit versions of the software. If you wish to know more about the best tool for repairing corrupt SQL databases or to buy it, browse through the official Stellar Info website today.
Conclusion
SQL databases act as the backbone of businesses as it contains sensitive data. In the case of corrupt or damaged databases, companies may become dysfunctional, which can severely affect their market reputation and compel them to suffer significant monetary losses as well. Several reasons may lead to a corrupt database, such as abrupt power cut-off, system failure, hardware/software issues, etc.
Therefore, to repair the database and make it fully functional is crucial. Experts use several manual and automated tools to fix this issue. For instance, admins use SQL Server Management Studio and T-SQL commands, such as DBCC CHECKDB for this purpose. However, these methods cannot perform complete SQL recovery and may delete the data permanently.
Leveraging Stellar Repair for MS SQL, a third-party SQL recovery tool for repairing corrupt SQL databases could be a fruitful decision. It helps to repair and rebuild the database in a quick time so that companies can get back to their work at the earliest. You can buy this software from the official Stellar Info Website.