SQL server error 3301 is associated with transaction log files of SQL server database. The overall activities or operations that take place within the database gets recorded in the transaction logs. In the event of application breakdown, these logs help in recovering data by performing appropriate actions.
Transaction logs hold the details of each and every operation that is been performed on MDF and NDF files. Operations such as insert, delete, modify, etc. are entered in the order in which they have performed.
During database recovery process as well as while implementing other activities, the SQL server scans all the recorded logs. If any invalid entry is been recorded by the server while scanning the logs, SQL error 3301 will occur. The error text appears similar to:
"The transaction log contains a record (logop %d) that is not valid. The log has been corrupted. Restore the database from a full backup, or repair the database".
SQL server error 3301 appears with distinct state and it is important to understand all associated state in order to execute further actions:
SQL Error 3302: This error message appears when the user is unable to backup database as well as restore database snapshots.
The error message appears similar to this:
"Redoing of logged operations in database '%.*ls' failed to reach end of log at log record ID %S_LSN. This indicates corruption around log record ID %S_LSN. Restore the database from a full backup, or repair the database".
SQL Error 3313: A roll-up error that takes place while redoing recovery operation and puts database to SUSPECT mode. The corresponding error text message appears similar to:
"During redoing of a logged operation in database '%.*ls', an error occurred at log record ID %S_LSN. Typically, the specific failure is previously logged as an error in the Windows Event Log service. Restore the database from a full backup, or repair the database."
Note: For SQL error 3314, same text message will appear as for error 3313. The reasons, resolution as well as the SQL server versions for this error are also same as that of SQL error 3313.
SQL Error 3315: This error message is associated with the following version of the respective application:
The error message that takes place on SQL server screen appears similar to this:
"TaskName"is paused because the required tape "MediaLabel" is not available in the library "LibraryType","Library"
"During rollback, the following process did not hold an expected lock: process %d with mode %d at level %d for row %S_RID in database '%.*ls' under transaction %S_XID. Restore a backup of the database, or repair the database".
SQL Error 3316: While executing undo operation on SQL database; if a row remains hidden or is difficult to found, error 3316 takes place.
The error message will appear similar to:
"During undo of a logged operation in database '%.*ls', an error occurred at log record ID %S_LSN. The row was not found. Restore the database from a full backup, or repair the database".
Since, the above mentioned SQL error occurs due to corrupted or invalid transaction log records; the resolution to these issues is data restoration from available backup files. It is always recommended to schedule backup on regular basis as it helps preventing data loss in critical scenarios.
SQL backup files are the major medium for rectification of these error messages. Also, when data is restored from most recent backup files, the access to maximum database components can be gained. Therefore, through backup restoration technique, the SQL database items can be restored back along with the complete components in their original format and structure.
The above stated error messages can be resolved using manual procedures such as DBCC implementation, backup restoration, etc. But these procedures are not much reliable and may result out in data loss. Therefore, SQL Server database recovery tool can be used for recovering data from database tables and other components. The data can be recovered from corrupted MDF and NDF files as well as the data that is been deleted accidently can also be recovered using the tool.