How to Fix SQL Server Page Level Corruption
Microsoft SQL Server is a SQL-based relational database management system designed for use in corporate applications, both on-premises and in the cloud. Each page of SQL server consists three sections- Header, body and slot array. When any of the data changed from any part of the page via hardware failure, then in such case a user will unable to open that page of the file. This is called SQL Server page-level corruption which may occur due to several reasons.
SQL database is the topmost database that a user wants after server. It has many features and advanced interface that make it very simple and easy-to-use server within the organization. But just like in any other database, users sometimes encounter bugs in SQL database as well.
Reasons behind Page Level Corruption in SQL Server Database
Before directly jumping to the solution to repair and solve SQL Server page-level corruption, a user needs to understand the reason behind it.
1. The most common reason behind database corruption is hardware malfunction or hardware failure.
2. Whenever there are some internal issues in the SQL Server, then it results in corruption in SQL database.
3. The SQL Server database is opened and there is an unexpected shut-down.
4. The page-level corruption in SQL Server can be due to virus intrusion also.
Reasons behind Page Level Corruption in SQL
The basic unit of storage in an SQL database is a page; all database information is stored in the form of pages. SQL Server database files have the MDF and LDF extensions. So basically, all LDF and MDF files are logically divided into several hundred pages and each individual page has its own location on the server. In case of page-level corruption in SQL server, each of these pages starts getting corrupted. Because it is easier to fix small chunks of data, than the whole file, it is generally recommended to fix individual pages before you try to fix the file.
But before you start to fix this problem, then knowing its actual root cause is very essential. So let’s see some of the prominent reason why does SQL page-level corruption happen?
1. The number one reason for page level corruption in SQL is the hardware malfunction. If there is a problem in the hard disk, it is the most likely reason for the corruption. Therefore, you must regularly monitor your hard disk, the server box, and other hardware in the system to avoid facing a problem like this.
2. You must ensure that the power supply to the server is regulated. Power supply problems when the database is running can also lead to page-level corruption.
3. Take care while downloading new software to the server. If the server is infected by a virus or a malware, it too could lead to damage.
4. While we know that one of the best practices of maintaining a healthy server is to keep it updated with the latest patches. However, installing the wrong updates could also, unfortunately, cause corruption.
5. Sometimes, a problem in the server itself that cannot be diagnosed can potentially lead to corruption.
6. If due to any of these reasons you start noticing glitches within the server and suspect corruption, you should take a backup of all data in the database as it is and initiate remedial procedures.
How To Fix SQL Server Page Level Corruption?
In order to fix the SQL Server page corruption problems, admin uses various strategies such as replication, disaster recovery plans, database monitoring, etc. But, there are some situations in which even admin is not able to resolve the issue. In SQL 2005 and above version, there is a feature called Page Checksum is used to detect the damage scale in the database. If the issue is not readable by SQL server in the SQL database, then complete restoration of the database is required. However, if there is minor corruption and lesser pages are infected, then DBA is advised to use DBCC utility.