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Learn about the Misconceptions around SQL Database Corruptions

SQL database corruption is the issue every database admin has to face at some point in their lifetime. But do you know what can cause you more trouble than a corrupt database? It is the misconceptions around SQL database corruption. These myths can actually worsen the situation for SQL database and its users. Therefore, it is crucial that users have the full knowledge of SQL Database corruptions and the myths and reality surrounding it.

Some Common Myths Regarding Database Corruptions

Let’s explore which ideas about database corruption are basically misconceptions.

  • Server Restart/ Reboot is the Quickest Method to Fix Corruption: This is one of the most prevailing misconceptions about SQL database corruption. SQL Server reboot or Windows Server restart will not fix the corruption, rather, it will possibly make the situation worse by putting it in Suspect mode. Detaching a database that is already in Suspect mode will make it impossible to fix the corruption ins future. A corrupt database page requires repairing or restoration, not reattaching.
  • Detaching and Re-attaching the Database will Resolve Corruption: This is another malpractice performed by many database admins. Instead of repairing, it will make the database recovery more difficult.
  • Repetitive Running of DBCC CHECKDB will Do Away With All Corruptions: In some extremely rare cases, re-running the DBCC command may repair one or two minor level corruption from SQL database. But this is not a recommended solution as the chance of success is very rare.
  • Applying Repair Command is harmless: If you believe that running commands to repair will not cause any harm to your database, you are wrong. If you are running DBCC CHECKDB REPAIR_ALLOW_DATA_LOSS, it is possible that your database may face some significant amount of data loss. So, always keep a backup of your database to avoid this sort of situation.
  • To Execute Repair Commands, DBCC CHECKDB is Not Required: No, DBCC CHECKDB commands are used for the purpose of checking physical and logical integrity complete set of objects of any particular database. Before and after running the database repairing command, users have to run DBCC CHECKDB. It is not possible to repair database using manual command without running DBCC CHECKDB.
  • Running Repair Command Alone Assures Corruption Removal: Wrong! The success of Repair command in order to corruption removal depends on many factors. For this reason, its result will vary depending on the severity of the damages done to the database. So, it is mandatory to run DBCC CHECKDB command after repairing. It will help users to find out more critical corruptions and confirm the success of Repair command.
  • Incomplete Lengthy Operations Lead to Corruption: Many of us believe that if an operation is going on for a long period of time, interrupting it halfway will cause damage to the database. This is not true at all. Database corruption occurs only when there is a physical level corruption (e.g. bug, virus) in the Server.
  • DBCC CHECKDB is All-In-One Solution for All Corruptions: This is not quite the scene. The Repairing command of DBCC CHECKDB has only the limited capability when it comes to fixing corruption from SQL database. There are many corruptions that repair command is unable to fix, like PFS Page header corruption, Metadata corruption, Common value corruption, etc. If used in case of these corruptions, it will end up extract data in a lengthy process with no result. Moreover, REPAIR_ALLOW_DATA_LOSS command often leads to data loss. Restoration from last good backup is the most useful method in such cases.

Conclusion

There are numerous misconceptions around SQL database corruption in the industry. Here, we have focused on some of the most common myths regarding database corruption in SQL Server. We expect that the users will gain knowledge from this post and be able to take the right decision once the database becomes corrupt. SQL Server experts recommend having a regular backup of the entire database to avoid inconvenience during database corruption. In case any corruption persists in the database, then one can use SysTools MDF Recovery tool to repair corrupted MDF/NDF File of SQL version 2017, 2016 & all below versions.

 
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Posted by on February 13, 2019 in General topics

 

Method to Backup and Restore SQL Database

If you are an SQL user, you must back up your SQL database to save your business-critical data from getting lost/ deleted permanently. Only regular data backup can safeguard your data from various mishaps like end-user error, hardware issues, etc. Just by knowing the importance of backup is not suffice: users need to know the procedure in detail. This post will tell you some of the trusted methods to backup and restore database in SQL Server.

How to Backup and Restore Database in SQL Server

We will be providing you with a step-by-step guide to both the processes: SQL database backup and restore. Read the following segments to know more about it.

  • How to Backup SQL Database

Using this method of SQL Server Management Studio (SSMS), users can back up the database that can be used at any crucial moment.

a. Open SSMS and go to Object Explorer. Select the Servername and expand it.

b. Expand Databases to choose a user database. Or you can expand System Databases to choose any system database.

c. Right-click and hover your cursor on Tasks>> click Back up to get the Back Up Database dialog box.

d. Confirm the name of the database from the drop-down list of Database. If you want, choose another database from the list.

e. Choose Full from the drop-down list of Backup type. (You can also choose SIMPLE or BULK_LOGGED)

f. To create the copy-only backup, select the checkbox beside the same option.

g. Select the radio button beside Database under Backup component.

h. Under Destination section, choose your destination for backup from the Back up to drop-down list. Click Add to include extra backup objects and/or their destinations. You can also remove a mistakenly added backup destination by selecting it and clicking on Remove.

Note: To back up a transaction log, run this script. In this example,l get created in AllSalesWorks_FullRM_log1.

  • How to Restore SQL Server Database from Backup File

If the SQL database encounters some issues that cannot be resolved, the last good backup of the database can be restored to fix the problem. In this section, we will describe the process to restore SQL database from the backup file.

For Full Database Restoration

a. To execute this process, start SQL Server Management Studio (SSMS), select the option Databases.

b. Right-click on it and choose Restore Database to open a window.

c. Click on the radio button select From Device under Source for restore section and then click on the Browse icon.

d. Specify Backup window will open. Click on Add and go to the location where the flat files are stored. Select the first backup file from the list as it is the Full backup file.

e. Click on OK. The file will get added to the Specify Backup window. Click on OK again.

f. Choose the target database where you want to restore the backup file by going to the section “Destination for restore.” Under “Select the backup sets to restore” section, check mark the database file chosen earlier.

g. Select Options from the left pane and then do these steps:

  • Check the box beside Overwrite the existing database (WITH REPLACE) under ‘Restore potions’ section.
  • Under ‘Recovery state’ section, choose Leave the database non-operational, and do not roll back uncommited transactions. Additional transaction logs can be restored. (RESTORE WITH NORECOVERY)” radio button.

h. Click OK and the restoration will be done.

I. Perform these steps for every incremental backup file, which includes the .tm file. When you reach a point when you have to restore the point-in-time file, follow this second method after “Restoring” message appears.

For Point-in-Time File Restoration

These steps need to be performed for the restoration of last incremental file that contains the point-in-time:

a. Start SQL Server Management Studio to right-click on Databases>> click Restore Database.

b. Choose From Device option under Source for restore section and click Browse.

c. On the next window, click on Add to go to the location of the incremental backup file with the point-in-time that you want to restore. Select that file and click OK.

d. Click on OK again. Select the added backup file in Select the backup sets to restore segment.

e. Choose the destination database in Destination for restore section. Click on Browse button next to “To a point in time” to make ‘Point in time restore’ window appear.

f. Enable ‘a specific date and time’ option and select the date and time.

g. Click on OK>> Options (left panel)>> Overwrite the existing database>> Leave the database ready to use by rolling back uncommitted transactions. Additional transaction logs can be restored. (RESTORE WITH RECOVERY)

h. Click OK to perform the process. In the restored database, you will only view the changes done to a particular point-in-time.

SQL Backup Recovery: The Ultimate Way to Restore Healthy and Corrupt BAK File

As we can see, the manual restoration process is a long one. Moreover, this process does not support restoring data from corrupt BAK file. To avoid these problems, SQL bak File Repair is a reliable solution. In some easy steps, users can restore their corrupt or healthy .bak file to SQL database.

a. Launch the tool and Add BAK file.

b. The software will resolve all the issues and offer full Preview. Click on Export.

c. You can export as SQL Server Database or as .csv script.

Concluding Words

In case you are wondering about the process to backup and restore SQL database, here are some of the approaches you can follow. All the methods mentioned here have been tested and users can execute them without any worry. If your backup file is damaged or you prefer an easy way of restoration, you must go for SQL Backup Recovery Tool.

 
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Posted by on January 8, 2019 in General topics

 

Create SQL Server HA and DR using FCI and AOAG

One of the most tricky subject for any SQL Server DBA or SQL server consultant How to build HA ( High Availability ) it is not something Complex, but it need to be list down all of the points and the requirements before going for this project and when we talk about High Availability We should consider two technology FCI (SQL Server Failover Cluster) and AOAG (Always on High Availability Group) both technologies will give you the same feature ( High Availability ) to save your DB from any disaster  can be happened in your DB center , As you know AOAG is new technology released with SQL Server 2012 and Microsoft added more features on it in SQL Server 2016, 2017 and 2019 as well . So really I recommend it for HA solution. Also, it will give you the availability to split your transaction between multiple instance one as RW (Read-write) it is called Primary, and the other instance will work as R (Read only), and it is called secondary server.

Now I leave you with the training video to know How you can build SQL Server HA and DR using FCI and AOAG


Training video published by Mr. Musab Umair  Microsoft SQL Server DB Consultant you can follow him on his LinkedIn account (https://www.linkedin.com/in/musabumair/)

Keep following our community to know all of the new technologies and features in SQL Server

 
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Posted by on November 6, 2018 in HA Clustering

 

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How to create a SQL Database in Azure

How to create a SQL Database in Azure

(A Step by step procedure)

I am writing this blog and explaining how to create a database in Azure. As we know that Azure is a cloud computing service provided by Microsoft and is becoming popular in the world. As a DBA we need to know how to work in a cloud computing environment and therefore for the ease I providing a step by step solution for creating a database in Azure.

sql-database-windows-azure

Explanation:

First of all we need to login to Azure portal and need to check for SQL Database options as it will be on the left hand side as given in picture below.

SQL Database Options

As soon as we click on SQL database option, a new windows will open up as given in picture below:

pic 1

Here we can see in this picture that there is no database available. Now we have to create a new database and for that we need to click on Add button on the top as shown in picture.

As we click on add button so it will display a new windows which requires the information to fill in to create a database.

pic 2

pic 3

Here we need to provide the information as database name, subscription, resource group (if existing then use that and no need to create a new resource group for each database), another option here elastic pool which is already discussed in my previous blog , go through if not read

https://mirzahusain.wordpress.com/2018/08/06/sql-database-as-a-service-in-azure/

As this is a test database which I have created so not using elastic pool and simple creating a standalone single database in Azure. Rest settings pricing and collation we need to set here as per our requirements or choose default.

One more thing which is important that is location we need to choose as I have chosen East US , you may choose as per your company requirement and policies, for the test purpose you may choose any location and just try and hit.

pic 4

Check and fill all the option carefully as shown in the above picture and then hit the create button.

The deployment will start to create the database. I have created here the database named as “MirzaDB”. You would be getting the alert in the alert section as soon as deployment succeeded.

pic 5

Now database has been created and we can explore it by checking its size and other details as below in different pictures.

pic 6

Looking forward your likes & comments!

Mirza Husain

 

 

 

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How to Fix Microsoft SQL Server Error 926 Instantly

Microsoft SQL server is the most popular database management system. It provides flexibility to the database administrator for managing the database. But, sometimes it creates numerous errors in different stages while working with the SQL server database. SQL database suspect error 926 is one of them, which creates hurdles in SQL transaction. Sometimes, it also vanish the smooth working of SQL server as it makes database inaccessible for the user.

Hence, this article will tell you the best solution on how to fix Microsoft SQL Server error 926. Before going towards the solution, let us discuss the symptoms and reasons behind SQL Server error 926.

SQL Server Error 926 – Find Out Reasons

  • The SQL database might be marked as suspected
  • When malware defect occurs in the hardware of the machine<
  • If corruption found in the header part of the system file
  • Sudden shut down of the server application also leads the error

How to Fix Microsoft SQL Server Error 926

You can resolve SQL database suspect error 926 with help of any of the solution discussed below:

Solution # 1: Resolve SQL Error 926 Using Server Management Studio

  1. Launch the SQL Server Management Studio on your computer system.
  2. After that, go to the Object Explorer >> Server Instance >> Stop option.
  3. Now, minimize the management studio & open the Control Panel on the system.
  4. After that, change the view screen to Large icon & click on the Administrative Tools.
  5. In this step, select the Services option to proceed further.
  6. Here, search for the SQL Server (MSSQLSERVER), right-click on it & choose Stop option.
  7. Close the control panel window & launch My Computer or Computer on Windows. In the computer, go to the location where SQL data has been saved.
  8. Select MSDBDATA and MSDBlog files and move them to another location.
  9. Now, go to the location where you had moved the file in the previous step and copy them.
  10. In this step, restore the management studio window & go to the Object Explorer section. Now, right-click on the Server Instance & choose Start option.
  11. Finally, click on the Refresh button of the Management studio in order to update the changes.

Limitations of the Manual Approach

The above discussed manual method involves a lot of brainstorming effort and it is a time consuming process.To fix SQL Server error 926, there is a long and complex command to be executed. There might be the possibility that you might make mistake during command execution. It also takes a lot of time to remove the error Microsoft SQL error 926 and to recover the SQL server database. Moreover, the manual procedure is completely unsuitable for the non-technical or less experienced users because this process contains the totally technical term. Thus, to replace the manual approach, an effortless approach is described which overcomes all such consequences of the manuals.

Solution # 2: Fix Microsoft SQL Server Error 926

To overcome all such drawbacks, users are suggested to take help from a third-party solution named as SQL MDF Repair Tool. The tool repairs corrupt MDF / NDF SQL server database file of SQL Server version 2017 & all below version. The software gives you two different options for exporting. One can export recovered database in SQL server database and as .sql script. Moreover, by using this Professional software, Microsoft SQL Server error 926 can be easily fixed without any hassle.

Final Words

In this article, we have discussed about SQL server error 926 and different methods to fix this error. The manual approach is available to fix SQL error 926 Suspect but it has many consequences. Hence, in order to perform a simple, easy and effortless recovery procedure, users can use SQL recovery tool. It is the easiest approach to remove SQL Database suspect error 926

 
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Posted by on September 19, 2018 in DB corruption

 

SQL Server 2017 on Linux

Hello, followers, I need to share with you some tips in SQL Server 2017 on Linux

  • SQL Server 2017 supported Red Hat, SUSE and Ubuntu
  • You need 3.25 GB of memory to run SQL Server Enterprise on the Linux operating system
  • Not like Windows Server you can install multiple instances on the operation system, Linux supported only one SQL Server instance
  • Hostname of the SQL server should be less than 15 Characters
  • File System has a different configuration in Ubuntu and SUSE should be EXT4 but in Red Hat should be EXT4 and XFS Files.
  • Remote databases can’t be stored on NFS system
  • SQL Server Native GUI still not supported in Linux system till this moment
  • Cannot connect to the SQL instance on Linux from the management studio installed on Windows Server
  • The maintenance plan, Management Data Warehouse, distributed transactions, and the Data Collector are not supported in SQL Server /Linux
  • If you have SQL version less than 2017 and you need to migrate it to Linux , Recommended to upgrade it on Windows server to SQL 2017 than you can take backup from DB and restore it on Linux or Attach / De attach and in the restore DB from windows to Linux you need to use “WITH MOVE” T-SQL statement
  • SQL Server 2017 unsupported feature on Linux (transactional replication, merge replication, stretch DB, polybase, distributed queries with third-party connections, system extended stored procedures, file tables, CLR assemblies with external access or unsafe permissions set, and buffer pool extensions. Database mirroring, agent alerts, managed backups, the SQL Server browser and the machine learning services that include support for the R and Python programming languages, are also not supported at the time of this recording)

I know this a lot features in SQL Server 2017 not supported in Linux but personally, I am so proud about this results it is the first time for Microsoft to see SQL Server on another operating system (Red Hat, SUSE or Ubuntu)

References :

https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-release-notes?view=sql-server-2017

https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-editions-and-components-2017?view=sql-server-2017

https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-security-overview?view=sql-server-2017

https://www.theregister.co.uk/2017/09/27/sql_server_2017_whats_new_and_on_linux_whats_missing/

 

 
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Posted by on September 15, 2018 in SQL Server 2017 on Linux

 

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SQL Server Torn Page Repair: Without Worrying About Data Loss or Corruption

It can often be bugs and errors in fetching data from the server. This can leave system administrators baffled as all work comes to a standstill. Incomplete or incorrect transaction cause confusion among employees working on the different sections of a database.

One such frequent issue is the SQL Server torn page error. It can be quite a hassle for a non-technical user facing such a situation. There are ways to fix it easily without worrying about any data loss. This post covers all there is to know about this topic. Continue reading to find out more.

What is the Torn Page in SQL Server?

It is the inability of the server to fetch a particular data during a transaction. It is caused when an Input/Output header tries to access a page that was written incorrectly to the disk. It reports a message saying ‘I/O error (torn page) detected during read’. The reason for this can be primarily contributed to power failure causing partial writes. Other factors include damaged disk or other hardware to which data is being written to. If a torn page is detected by SQL Server, it will sever all connections as the requested data is inaccessible. During the restore process, detecting a torn page sends the database into SUSPECT mode.

sql server torn page repair

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