How to perform SQL Database Recovery
Recovering data by checking SQL database inconsistencies
People working on MS SQL server may stumble across 'False Positive' while running DBCC CHECKDB statement .This is done to check database consistency. It can occur due to inconsistency of the MDF file created with MS SQL server. Database corruption and missing database object is particularly due to database inconsistencies.
At this point of time database is almost inaccessible and user can loose the stored data. For any such situation it is important for SQL server to perform impeccable SQL recovery with professional MDF recovery and getting through with the issue as early as possible.
Consider a real time scenario,each time user tries to check his/her MDF database file with the help of DBCC CHECKDB statement on SQL Server it will report to consistency error of database tables. Although,while running DBCC CHEKCTABLE state to repair SQL table,for MDF recovery and repairing inconsistencies there will be no display of errors. However, you can also be hit by false positive situation displaying the following error:
“DBCC CHECKDB is performing an exhaustive search of indexes for possible inconsistencies.”
“SQL Server has encountered 1 occurrence(s) of I/O requests taking longer than 15 seconds to complete on file in database.”
For such situation, if you check the Applicant Event simply log onto MS SQL server and you can find such entires:
Msg 8978, Sev 16, State 1, Line 1: Table error: Object ID 1789795471, index ID 1, partition ID 72057602467495936, alloc unit ID 72057602585395200 (type In-row data). Page (1:2387522) is missing a reference from previous page (1:2387521). Possible chain linkage problem. [SQLSTATE 42000]
Msg 8958, Sev 16, State 1, Line 1 : repair_allow_data_loss is the minimum repair level for the errors found by DBCC CHECKDB . [SQLSTATE 01000]
Such errors are due to inconsistencies issues or corruption of MDF database file. Reason for corruption of the MS SQL Server is due to sudden system shutdown, virus infection, abrupt Server shutdown, application failure, faulty hardware etc. Although with SQL database recovery you easily bring out the corrupt or inaccessible database in a feasible working condition by restoring from a valid and recently updated backup.
Once the SQL database is restored run the database defragmentation. Moreover, if required backup is not available then perform MDF recovery to get the inaccessible SQL data.