Lesson 7: Restore a database to a point in time

THIS TOPIC APPLIES TO: yesSQL ServernoAzure SQL DatabasenoAzure SQL Data Warehouse noParallel Data Warehouse

In this lesson, you will restore the AdventureWorks2014 database to a point in time between two of the transaction log backups.

With traditional backups, to accomplish point in time restore, you would need to use the full database backup, perhaps a differential backup, and all of the transaction log files up to and just past the point in time to which you wish to restore. With file-snapshot backups, you only need the two adjacent log backup files that provide the goal posts framing the time to which you wish to restore. You only need two log file snapshot backup sets because each log backup creates a file snapshot of each database file (each data file and the log file).

To restore a database to a specified point in time from file snapshot backup sets, follow these steps:

  1. Connect to SQL Server Management Studio.

  2. Open a new query window and connect to the SQL Server 2016 instance of the database engine in your Azure virtual machine.

  3. Copy, paste and execute the following Transact-SQL script into the query window. Verify that the Production.Location table has 29,939 rows before we restore it to a point in time when there are fewer rows in step 5.

    -- Verify row count at start  
    SELECT COUNT (*) from AdventureWorks2014.Production.Location  

    Row count of 29,939 is displayed

  4. Copy and paste the following Transact-SQL script into the query window. Select two adjacent log backup files and convert the file name into the date and time you will need for this script. Modify the URL appropriately for your storage account name and the container that you specified in Lesson 1, provide the first and second backup file names, provide the STOPAT time in the format of "June 26, 2015 01:48 PM" and then execute this script. This script will take a few minutes to complete

    -- restore and recover to a point in time between the times of two transaction log backups, and then verify the row count  
    RESTORE DATABASE AdventureWorks2014   
       FROM URL = 'https://<mystorageaccountname>.blob.core.windows.net/<mystorageaccountcontainername>/<firstbackupfile>.bak'   
    RESTORE LOG AdventureWorks2014   
       FROM URL = 'https://<mystorageaccountname>.blob.core.windows.net/<mystorageaccountcontainername>/<secondbackupfile>.bak'    
       WITH RECOVERY, STOPAT = 'June 26, 2015 01:48 PM';  
    ALTER DATABASE AdventureWorks2014 set multi_user;  
    -- get new count  
    SELECT COUNT (*) FROM AdventureWorks2014.Production.Location ;  
  5. Review the output. Notice that after the restore the row count is 18,389, which is a row count number between log backup 5 and 6 (your row count will vary).

    Results pane showing the row count after the point in time restore

Next Lesson:

Lesson 8. Restore as new database from log backup