Different Types of Database Corruption in SQL Server

Aisha | October 15th, 2018 | SQL Server

Microsoft SQL Server is the advanced relational database management system used by businesses or professionals. It also improves the user interface and features of SQL database that makes it a useful application for managing bulk data. Although the functionality of this application, the database created by it is more prone to corruption, which results in the inaccessibility of data. Therefore, in the upcoming section, we will discuss different types of database corruption in SQL Server and also recommend a third-party solution for the same.

Common Reasons For SQL Server Database Corruption

There would be several reasons that can lead to database corruption in SQL Server. Microsoft SQL Server contains two different types of file system, i.e., MDF and NDF. MDF is the primary file system, which saves complete information and if the MDF file gets corrupted, then the database will be affected. Follow various reasons as listed below:

  • SQL Page Level Corruption
    The major cause of SQL Server database corruption is SQL page corruption. All data information of Microsoft SQL stored at the page level. In addition, the page is the basic unit for storing data and a basic level of I/O function in the server. It consists of data or full details about the physical layout of a data. In any case, the pages in database corrupt or damaged, which stores appropriate data to preserve database constantly. It has the same layout for storing all pages of the SQL database server. It usually contains page header of 96 bytes and body of 8096 bytes. If any data inconsistency occurs in all pages, it may cause partial or database inaccessible. As such pages will either be stored in them or acts as a pointer to another page. The missing page may disturb the database index that may result in page corruption.
  • Page Header Corruption
    Every SQL server database page involves header that maintains the control over the way of data information stored in the page. There are different fields of the header, which helps to verify the consistency of the database storage structure. Anyone of them helps to provide a navigation to pages smoothly, which makes up the table.
  • Index Corruption in SQL Server
    An index is the most important component in a relational database that helps in the recovery of the database from a table. These components are created for both tables as well as views. Moreover, it contains two types of indexes as listed below:

a) Clustered: The database might have only one cluster index as it assists in the physical sorting of a database.
b) Non-clustered: There are approximately 249 non-cluster indexes in the table or view. It gives the pointer to the corresponding index point rather than sorting database.

Thus, if there is any corruption in cluster or non-cluster index as a result in partial or complete data loss.

  • Boot Page Corruption
    Boot page is like as the file header, which provides the Metadata information. But, instead of giving the data information, the boot page provides whole information about a database. It is placed in the initial data file on page 9 of the database. It can save all details such as the creation date of a database, database ID, compatibility level, and so on. It helps in a systematic consistency checking database.

Manually Repair Corrupt Database in SQL Server

In some cases, the main cause of SQL Server database corruption is I/O sublevel system. This problem will arise with all the drivers, controllers, or other drivers. Therefore, it is advisable first you have to check for hardware related issues. Further, there is an inbuilt program, i.e., Transact-SQL command, which helps to verify the consistency of the database. It is also called DBCC CHECKDB. It also helps to test the database for physical or logical corruption level. It can check all links between pages, structural content, index pointers, index pages and so on.

Now, What’s Next?

Download SQL Recovery software on your desktop to repair both primary and secondary SQL database. This tool is designed with numerous advanced features to execute the data recovery. This application is capable enough to restore deleted SQL Server database tables without any difficulty. The software allows recovering all tables, functions, stored procedure, views, rules, triggers and Primary Key, data types, Unique keys, and other SQL database components. It is compatible with SQL Server versions 2017 and all below versions.

Summing Up

In this blog, we have discussed different types of database corruption in SQL Server in a detailed manner. Along with it, a manual solution is also explained to fix SQL Server database corruption. According to experts, if this method fails to resolve large size database errors, then users can use the above-mentioned tool. It is the best solution, which helps to fix corruption issues in the SQL database server.