Posts Tagged ‘DELETE’

Today I thought of writing an article on how to remove all the partitions from a disk so you can re-use the disk.

If you tried removing existing partitions using the Computer Management (type computer management on the start menu to open it) tool in Windows you will find that, you can delete partitions by right clicking on the partition / volume and clicking on Delete Volume option.

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However you will notice Computer Management is useless on some of the protected volumes since the options to work on them will not be available.In this case you will need to use the DiskPart utility in the Command Prompt.

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In the Start type Cmd or Command Prompt to open a command prompt. Then type DiskPart, it is a powerful utility which can even work on protected volumes.

In my case, I would like to work on Disk 3 to remove all the existing volumes on it. Below are the steps required to clean the drive.

1. Select the disk.

List all the disks by typing List Disk, this will list all the disks connected and active at the time in your computer including the disks connected via USB ports.

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Once you identify the disk you need, selection can be made by using the command Select Disk x. In my case Select Disk 3.

To confirm, list all the partitions on the selected list by using the command List Partition.

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2. Delete all partitions by using the Clean command.

Ensure the proper disk is selected by Listing all disks by command List Disk, the currently focused disk will have a star at the beginning since recovering disks is not easy.

Type Clean and press enter. This will remove all the partitions from the disk. You can check the results by re issuing the List Partition command.

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Close the DiskPart tool by entering the command Exit.

Computer Management will now show that the disk is uninitialized as below, Initialize the disk and create partitions / volumes as necessary to use it again.

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You can remove simple partitions by using the Computer Management tool found in Windows. Search for it on the Start menu to launch it.

But if it is a protected partition you will need to use the tool DiskPart. In the Start menu type Cmd or Command Prompt to open a command prompt. Then type DiskPart, it is a powerful utility which can even work on protected volumes.

To delete one partition, follow the steps.

1. List all disks by using the command List Disk.

2. Select the disk by using Select Disk x command.

3. You can confirm the disk by listing all the partitions on it by using the command List Partition.

4. Select the partition by using the command, Select Partition x command.

5. Delete the partition by command Delete Partition Override.

Override parameter needs to be passed if the partition is not a simple data partition.

You can confirm the deletion by re-listing the partitions on the disk by List Partition command.

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Recently while deleting a service application my system got unresponsive and while trying to create the service application again i constantly got the following error.

“An unhandled exception occurred in the user interface.Exception Information: An object of the type Microsoft.SharePoint.Administration.SPIisWebServiceApplicationPool named "SearchServiceApplication" already exists under the parent Microsoft.SharePoint.Administration.SPIisWebServiceSettings named "SharePoint Web Services". Rename your object or delete the existing object.”

This seems to be happening because one of the service application pools were not removed while deleting the service application. This can be removed by using PowerShell.

First load the SharePoint 2010 Management Shell by navigating to Start –> Microsoft SharePoint 2010 Products –> SharePoint 2010 Management Shell.

SPStartMenu

Then use the “Get-SPServiceApplicationPool” command to view all the existing service application pools.

Get-SPServiceApplicationPool

Now use the “Remove-SPServiceApplicationPool -Identity SearchServiceApplicationPoolName” command to remove the service application you want removed. If the service application pool’s name is having spaces remember to use double quotes.

Remove-SPServiceApplicationPool -Identity SearchServiceApplicationPool1

PowerShell will ask to confirm the deletion, after confirming the action, it will remove the service application pool.

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By now as you know, in this post I am going to discuss about two SQL commands we use regularly to clear data in our tables.

Usage

  1. DELETE FROM TABLENAME
  2. TRUNCATE TABLE TABLENAME

Even though they do a similar thing, there are some differences which makes them unique commands.

 

DELETE

TRUNCATE

1. Considered as Data Mining Language (DML) statement. Considered as Data Definition Language (DDL) statement.
2. Can be used to delete all or part of data in a table. Will delete all the data in a table.
3. Will log the actions. There will be no logging on record deletion.
4. Will use more locks. Will use fewer locks.
5. Will use more resources. Will use less resources.
6. Slow. Fast.
7. Will not reset the identity seed. Will reset the identity seed to 0.
8. Can be used to delete data in tables having relationships. Cannot use in tables having relationships.
9. Can be used in tables involved in log shipping or replication. Cannot be used in tables involved in log shipping or replication.
10. Transaction can be rolled back. No rollback.
11. Table may keep the empty pages. Can be released by running, SHRINKDATABASE (Database Name). Data pages related to the table will be de allocated and returned to the system.
12. Related Triggers are fired. Triggers are not fired.

 

If you used DELETE to fully remove all the records, you can reset the identity value by running the following command.

  1. DBCC CHECKIDENT (TABLENAME, RESEED, 0)

If you do have some rows left in table, simply replace 0 with the last identity column value. For example if you put 5 instead of 0 then the next record inserted into the table will have an identity column value of 6.

If you jus need to check the current identity value just use the following command.

  1. DBCC CHECKIDENT (TABLENAME, NORESEED)