Know the common SQL Server corruption errors and their solutions
MS SQL Server database is one of the popular and advanced relational database management systems, which is largely used by organizations and professionals. The improved user interface and advanced features of SQL Server make it one of the best database management tools for managing a large amount of data. Despite the usefulness of this software, the databases created by it are prone to corruption, which results in the inaccessibility of all the data.
Common reasons for the corruption of the SQL database.
SQL database can be damaged or corrupt due to many reasons, some of them are
More than 90% of corruption happens due to hardware failure
- Bugs in SQL server itself.
- Abrupt system shut down while the database is opened.
- Changes in SQL account.
- Virus infection.
- Upgrading SQL Server from previous versions to newer ones also, at times, results in the corruption of the database.
Whatever the cause of corruption is, you cannot get to understand it until you access the damaged data.
ERRORS IN SQL
While using MS SQL you get any of the below-mentioned error messages while trying to interact with corrupt data of your SQL database
- Msg 823 error in SQL Server
- Msg 824 (I/O error) in SQL Server
- Msg 825 (read retry) in SQL Server
- SQL Server Page Level Corruption
- Corruption on non-clustered indexes
- Corruption on data pages
- Metadata corruption Error
This error will indicate the data file (usually a .MDF file) and the operation can be read or write. It is calculated as the logical page is the offset number divided 8192.
This SQL Database error 824 is a logical Input/Output (I/O) error. A logical Input/Output means that the page is successfully read from the disk. However, there’s an error in the page itself. Moreover, a ‘logical consistency error’ clearly indicates effects on file due to corruption in the database where corruption is due to an I/O subsystem component that is faulty.
Msg 825 is often referred to as the read retry warning but technically the retry can be for a read or write operation. This message indicates if the operation was based on a read or write.
It is a page that was incorrectly written. We could say SQL Server Page-level corruption writes a bit for every 512 bytes in the page and it allows you to detect when the page is not successfully written to disk but does not tell you if the data stored to disk is exactly correct as a couple of bytes may have been written incorrectly. You can read about this error in detail Read more.
The probable reason for SQL database index corruption is the NOLOCK hint which causes the query to read the Table-values incorrectly or when the query reads the same values in the data many times.
Equivalent to a nightmare, page corruption in the SQL server jeopardizes all the crucial data saved on the server. The data becomes inaccessible even to administrators (with full privileges), thereby creating an obstruction in the workflow of the entire organization. The most common reason for page-level corruption in SQL is the hardware malfunction. If there is any problem present in the hard disk, it is the most likely reason for the corruption. So, you have to regularly monitor your hard disk, the server box, and other hardware in the system to avoid facing a problem like this.
Metadata is information about other data. In SQL Server, you can get SQL Server Database information using system views or functions.
It is when your system views, procedures, functions are damaged due to a blackout, a virus, hacker attack, hardware failure, failed upgrade, insufficient disk space, shutdown problems or other reasons.
The above-mentioned list is for common errors of SQL Server database corruption. However, there can be more error messages for the same as well. In such situations, many will recommend you that backups are always the best way to restore data, which is not completely true. Backup is useful for some cases only, but for the cases wherein you come across the corrupt database element very late, it does not work. This is because might be corruption spoiled your backup as well.
For such cases, use the SQL Database Recovery is recommended. This SQL Recovery software repairs corrupt SQL database files and recovers tables, indexes, keys, rules, constraints, triggers, and defaults. The understandable user interface of this software makes it possible to recover various objects present in MDF and PDF database files without much effort.
In this article, we explained some common errors occurred while you are working with SQL server. Also, there is a recommendation to solve these errors which is a third-party tool that recovers the SQL database in no time. I hope you find this article useful to understand errors in SQL.