One of most common logical consistency-based i/o error 8939, which a user may face at the time of SQL Server database corruption as shown in the figure:
SQL is a Relational Database Management System that is very useful for the management of database. It is used in numerous organizations for exchange of crucial files. However, sometimes it results in few error messages. One such error message is SQL Server error 8939. It does not allow users to access the files and creates hurdle in between of their work.
The error generally occurred by the corruption in the database. It could be a minor or severe corruption. Various factors lead to this damage in SQL database such as attack from malicious virus, wrong settings or updation in SQL Server, abrupt shut down or system or a running program, power failure, etc.
Now, to know the consequence or outcome of the error, let us go through this query as mentioned below:
“I have bulk of database in SQL Server, which is so easy to access. However, last night when I tried to open a file I received an SQL error code 8939. Even the fear of database corruption is a nightmare to me as I have so much crucial files in this platform. Therefore, I have attempted it for one more time to open that file, but even then, I have received the similar error. I was shocked and started to search for a relevant solution. However, I was not able to find any way to get out of this situation. Finally, tired from all the efforts, now I am seeking for a help to fix 8939 error code in SQL as soon as possible. Please help me out if you have any trick to fix it.”
As we all know, one of the easiest and common to repair the data of SQL Server is DBCC CHECKDB. You need to run this command with the option of REPAIR_ALLOW_DATA_LOSS. However, as the name indicates, it will result in data loss if the data is not easy to repair.
Now, apart from this the other two available options to repair the damaged SQL database is REPAIR_FAST or REPAIR_REBUILD. The first one is for backward compatibility and cannot execute repairing in 2005 database. In case the least damage, choose option REPAIR_REBUILD. For example, damage in non-clustered index. You can easily deal with such corruption by build the index once again. Moreover, it will keep the data safe means without any loss.
Nevertheless, it is suggested to use the repair options provided by DBCC CHECKDB, which may result in loss of data only if there is no option to fix it. Hence, for such cases backup is very useful. However, the backup should be free from damage. Run, this REPAIR_ALLOW_DATA_LOSS command in order to this. The database should be in a single user mode for the execution of repairing process and the syntax will be:
DBCC CHECKDB ('ran', REPAIR_ALLOW_DATA_LOSS)
Once you run this DBCC CHECKDB command, you will receive an error. Basically, you will get two results: one the data has been repaired and the other one is loss of data. One thing that should be noted is that the result displays as object ID for a table under which the damage happened and an index ID that in this scenario is 0 due to the non availability of indexes on table.
Therefore, at this point, you have lost some data and it was of a data page, but one page one. However, how much data has been lost exactly is the question. This will be revealed by the option SELECT.
It becomes so simple to recover these rows in case you have an updated and good backup. We are considering that you do have a good backup. Now, with this you can restore the lost tables and synchronize two tables for the rows that are missing. You can synchronize two tables easily by INSERT INTO statement.
Now, as mentioned above that DBCC CHECKDB command results in a loss of data. Moreover, sometimes it is not possible to fix SQL Server error 8939 with help of this strategy. Therefore, users can opt for SQL Database Repair, which is one of the most useful products in repairing unhealthy SQL database. This is used by many professionals and has the capability to fix any kind of damage without any difficulty.
We all are aware about the importance of SQL in business productivity. Therefore, it becomes very important to resolve certain errors that come all of a sudden without any prior notice. One such issue that we have discussed in the above blog is SQL Server error 8939. We have learned the reasons, consequences, and the best possible solutions to resolve this problem and bring SQL back in working mode.