Follow these instructions from Restoring a Site to restore the XML backup

Stop Confluence (all following steps are in SQL Server Management Studio)

Identify any fields that have the datatype varchar, char, or text

select distinct object_name(object_id) from sys.columns
where system_type_id in (35,167,175)
and OBJECT_NAME(object_id) not like 'sys%'
order by 1;

Create a new SQL Server database configured as described in Database Setup for SQL Server

1. Right click the old database in Object Explorer
2. Click Tasks > Generate Scripts...
3. If prompted select the current Confluence database
4. On the Choose Scripting Options adjust the following options:
   
   1. Set Script USE DATABASE to false
   2. Set Script Full-Text Indexes to true
   3. Set Script Indexes to true
5. In the Choose Objects Types screen, tick Tables
6. In the Choose Tables screen, click Select All; click Next
7. In the Output Option screen, click Script to file; click Finish

1. Ensure you use the full words in find and replace, so you don't accidentally end up with values like 'nvarnchar' 

1. Select the new Confluence database in the Available Database dropdown
2. Click File > Open > File
3. Select the script from the picker
4. Click Execute

1. Execute the following query against the new Confluence database

   EXEC sp_MSforeachtable"ALTER TABLE ? NOCHECK CONSTRAINT all"

1. Right click the old database in Object Explorer
2. Click Tasks > Export Data... 
3. In the Choose a Data Source screen, select the old database from the dropdown; click Next
4. In the Choose a Destination screen, enter the server name you will be connecting to (this will most likely be the same as the original server) and select the new database from the dropdown; click Next
5. Select Copy data from one or more tables or views; click Next
6. In the Select Source Tables and Views screen, tick the top left box to select all tables; click Edit Mappings
7. Ensure the Destination schema name is correct (this should most likely be set to dbo) and tick the Enabled identity insert; click OK
8. Click Next
9. In the Run Package screen, ensure Run immediately is ticked and click Finish
   • Depending on the size of the database, and the speed of the database server(s) being used, this process will take time

1. Execute the following query against the new Confluence database to confirm all affected columns have been changed

   EXEC sp_MSforeachtable"ALTER TABLE ? WITH CHECK CHECK CONSTRAINT all"