The SQL server is well-known for its advanced functionality and versatility for years. It is widely used by business organizations, educational institutions, professionals, and students. The SQL database has been designed with an enhanced interface. It is an effective database management tool that helps it to take care of many databases on a single platform.
Though the SQL database seems to be the perfect database for users, it is highly prone to corruption. This often results in files unable to be accessed, making the extraction of crucial information impossible. To tackle this big problem, the database administrator should be aware of its causes, the problems faced, and the proper solutions that counter corruption errors to ensure the database are safe.
What are the reasons for SQL database corruption?
No matter how well you take care of your SQL server, it needs to be maintained on a regular basis. At the same time, a health check is recommended once in a while to ascertain that everything is in proper order and functioning correctly.
Many reasons lead to the corruption of data in the SQL database. If you closely examine the SQL server, you will find it has two types of systems for files. They are MDF and NDF- the are files is the major system that stores all the data information in total, and in the event of corruption, the whole database gets adversely affected. Some of the major reasons for SQL database corruption are-
- Failures in the hardware and software – Experts in database administration and management say that 95% of database corruption of SQL servers takes place because of-
- Bugs in the server
- Change in the SQL server account
- Virus attacks and infection
- Upgrading the SQL server from a previous version to a new one can result in the database becoming corrupt.
Whatever the reason for corruption, you will only get to know about it when you access the damaged data
Generally, you will receive any one of the following mentioned error messages when you try to interact with the SQL database’s corrupted data, like errors related to metadata corruption, corruption on the data page, and corruption on clustered indexes, etc.
In most cases, some IT managers recommend you take data backups to restore data; however, experienced experts from credible database administration and management company, RemoteDBA.com say this is not always the case. When it comes to database backups, they are good only for some cases.
If you come across the corrupt database error too late, the data backup plan will not work. This is due to the fact that the data has been completely spoiled by then by corruption.
Other hardware failures might cover errors in the memory, disk crashes, a disk full of errors, bad disk sectors, and other problems. Hardware failures can be caused due to design errors, poor quality control in fabrication, the use of components that are under-capacity in nature or overloading, and the wearing out of mechanical components.
When it comes to software failures, they include failures that are associated with the operating systems, application programs, the DBMS software, and others.
- Abrupt shutdown of the SQL server when it is open – When this occurs, it causes damage to the file system. The computer or the server often shuts down incorrectly when it experiences a sudden surge in power or anything similar that interrupts the process. At the same time, the data is written to the file, and it results in the files getting corrupted and damaged. Experts in database management and administration advise repairing or at least confirm the database system to curb data loss in the future. For creating or modifying a file system, you might need a repair. If the database check does not give you any signs of damage, it still might be in need of repair.
- File corruption – If one or even more of the files in the database system gets damaged, this results in database failure at the file levels resulting in corruption. These files can be corrupted because of multiple reasons. Primary files in the system often corrupt the whole database. They become corrupted mainly because a change has been made in the SQL database or accidental deletion of data and corruption in the file header along with other reasons.
For secondary file corruption, the SQL server becomes inaccessible. If you attempt to access this corrupt database, you will see different error messages in SQL server; Msg 825 read entry, etc.
There are some solutions for repairing a corrupt SQL database; however, they do not guarantee 100% recovery of your data –
- You can access the log files to restore the SQL database. However, these files are insufficient to recover the corrupt database in several cases as if the corruption is serious; the data backup files become corrupt.
- You can use another method to repair the corrupt database with console commands like DBCC DEBREPAIR and DBCC CHECKDB. They are useful when it comes to repairing database corruption issues that are minor; however, they are not sufficient for all instances of database corruption.
From the above, it is evident that though the SQL database is advanced and versatile, it is not free from the threats of corruption. Irrespective of how reliable your database management systems are, you can never ensure a transaction free from failures all the time.
If you want to prevent your SQL server from getting corrupted, you should get a database health check done. This evaluation will give you an insight into any signs of distress or problems your database might currently have. Suppose you do not have a qualified and experienced DBA team in your company. In that case, you can always seek the aid of credible remote database administration and management companies to conduct a health check on your SQL server. These companies often give you a report with all the issues and recommendations listed. With their support, you can protect your database’s health and protect it from corruption and subsequent data loss.
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