Practically all organizations that operate online utilize a database for storing information. According to G2, SQL database servers are incredibly popular and extensively used tools for deploying and maintaining such databases. SQL database server is efficient relational database software. Despite advanced features and numerous advantages of SQL database server, there is an inherent flaw. SQL databases may be susceptible to corruption at times. There is, however, no reason to panic. When users first realize a corruption issue, they start panicking.
Remember that this may prompt you to make some wrong decisions due to utter chaos, and your organization will be in a messy situation. You may run a repair or restore as your first step, this can result in massive monetary and data losses for your business, and these steps should be taken only when it becomes strictly necessary. Around 60 percent of small businesses fail to survive once they lose vital data. Within six months, they will be winding up their business. Experts believe that a database recovery process comprises three chief phases that may include the following:
Root Cause Analysis
Root cause analysis is a crucial step in the data recovery process and should not be undermined or overlooked irrespective of the specific data recovery method. It is a vital step in safeguarding your SQL server database and preventing corruption issues. When corruption takes place, it will occur again unless proactive measures are taken to tackle the situation and get rid of issue. The root cause analysis phase is dedicated to meticulously analyzing the transaction log, determining the last checkpoint, and creating an ATT or Active Transaction Table and DPT or Dirty Page Table. ATT is best for recording all active transactions involved improper shutting down of the database. DPT records point out exactly when your database actually got shut down
The redo phase involves forwarding all the changes or alterations recoded so far in the log. The DPT seems to have minLSN or minimum log sequence necessary for successfully recovering the database and initiating the redo operation needed for all other dirty pages.
Undo phase is all about holding the unfinished transactions identified in ATT. This phase goes towards ensuring database preservation. Once the database is retrieved, it goes online, and at this stage, you should not apply any extra transaction log backups.
Reason for SQL Database Server Going Into Recovery
For fixing and resolving the issue, it is essential to identify the underlying reasons for disruptions and errors. One of the reasons could be that the database is shutdown improperly, demonstrating that an uncommitted transaction must have been active when the database was abruptly shutdown leading to the log file deletion. Another reason could be inadequate hard disk space. Let us explore key reasons for SQL Servers to switch to recovery mode.
- Whenever a long-run transaction seems to cause disruption.
- When the transaction log files are huge in size.
- Presence of many VLFs or Virtual Log Files within the DB transaction file.
- A gigantic bug is present in the SQL database server.
Ways of Resolving SQL Database Server Recovery Mode Issue
A couple of steps are involved in bringing the SQL database Server from recovery mode to the usual mode.
- Start forceful repair technique by putting the database straightaway to the emergency mode. Emergency mode is used for marking the database as “Read Only”. It helps in disabling logging and grant access to the SQL system administrator. This setting allows inaccessible databases online. When the database is in emergency mode, you may start repairing the SQL database utilizing the command ‘DBCC CHECKDB’.
- Start detaching and reattaching the database simply by marking the SQL database server in emergency mode. Once you do that, start detaching the database and set it to online.
Repair Option or Forceful Repair is often utilized as the last resort if other repair options fail. The repair options of DBCC CHECKDB help recovery. Several repairing levels have no chance of data loss. Microsoft experts always emphasize the importance of a good backup for restoring and recovering SQL database errors. The database should be set to the single-user mode. Start running DBCC CHECKDB along with ‘REPAIR_BUILD’ Then initiate reactivation of multiple user modes and set the database to online again.
Consider Using a Reliable SQL Database Recovery Tool
You have easy access to several advanced SQL data recovery tools for recovering valuable data and providing a seamless solution to recover corrupted or damaged SQL data files. The recovery tool initially inspects and scans the corrupted files and displays the data preview so that you can see what you can retrieve. It facilitates the recovery of deleted records from damaged files, and then the records are saved in separate SQL data files.
It is challenging and hectic to troubleshoot an SQL database server in recovery mode post restart. A majority of the SQL databases will get stuck when in recovery mode because of diverse reasons.