Tag Archives: restore

Open Analysis Services Tabular Database Online

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Those of you who have been working with SSAS Multidimensional in the past probably know that you can connect online to their SSAS database via Visual Studio / Data Tools.
Open_SSAS_DB_Visual_Studio

Any change you make (and save) online, will be directly deployed to the server and is the visible to the end-user immediately. This can be very convenient if you want to quickly check something or do some hot-fixes (e.g. changing the MDX script).  But be aware, structural changes might require you to process the changed and dependent objects so be sure about what you are changing online, especially if you are connecting to a productive environment!

I am quite sure that everyone who works with SSAS Tabular has also tried this feature for his Tabular database and ended up with the following error message:
”You are trying to connect to <servername> server running in tabular mode using the Tabular Model Designer. The option to open an Analysis Services Database is supported for servers running multidimensional mode only.”
Open_SSAS_DB_Visual_Studio_Tabular

So this simply does not work out of the box. However, there is a neat workaround which allows you to connect to your online SSAS Tabular database and do any changes you want. The idea behind this is to use the online database as our workspace database.

The first thing to do is to open Visual Studio / Data Tools and import the existing database into a new Project:
Visual_Studio_Import_SSAS_DB_Tabular

Then you need to select your workspace server. If there is no pop-up asking your for a workspace server, then you have already configured a default one which will be used in this case. As we are going to change this in the next step again, it does not really matter which workspace server you choose.

Now you are asked for the database which you want to import – choose the one that you want to connect to online. Once the import process is finished, Visual Studio already creates a workspace database for you and names it as follows: “<VS ProjectName>_<NT-Username>_<random GUID>” – in my case it was “TabularProject1_gbrueckl_b44f11de-21f4-4d18-bf67-0c25652fceba”. Any change you make in Visual Studio will be deployed directly to this database. Closing Visual Studio will unload the workspace database from memory by default.

Having all this information you probably can imagine where all this is leading to. The workspace database name and server can be configured and are persisted in the user-specific “Model.bim_<user>.settings”-file located in your project folder:

Model.bim_gbrueckl.settings
<?xml version=“1.0“ encoding=“utf-8“?>
<ModelUserSettings xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance“ xmlns:xsd=“http://www.w3.org/2001/XMLSchema“>
  <ServerName>localhost\TAB2014</ServerName>
  <DatabaseName>AdventureWorksDW2012_Online_gbrueckl_b44f11de-21f4-4d18-bf67-0c25652fceba</DatabaseName>
  <DbRetention>OnDisk</DbRetention>
  <SnapshotBackup>DoNotKeepBackup</SnapshotBackup>
  <Annotations />
  <IsRecalcRequired>false</IsRecalcRequired>
  <IsImpersonationModified>false</IsImpersonationModified>
  <CheckForImpersonationWarning>false</CheckForImpersonationWarning>
  <RequirePastedTablesUpgrade>false</RequirePastedTablesUpgrade>
  <TruncatedTables />
  <IsPowerPivotMetadataScriptExecuted>false</IsPowerPivotMetadataScriptExecuted>
  <IsASImport>false</IsASImport>
  <IsPowerPivotImport>false</IsPowerPivotImport>
  <SelectedCompatibilityLevel>300</SelectedCompatibilityLevel>
</ModelUserSettings>

The settings you need to change here should be obvious – <ServerName> and <DatabaseName>. Change them to match your online SSAS Tabular server and database – the one you previously imported the project from.
But be sure to also change the <DbRetention>! Leaving the default “OnDisk” here would unload your database once you close Visual Studio what is definitely not what you want! You need to set this setting to “InMemory” to keep the database in memory – remember, we want to connect online but keep the database accessible once we are done.

Before you do all this changes you should close your Visual Studio solution completely to ensure there is nothing cached internally. Then simply open the .settings-file, do the changes described above and re-open your solution. If you have done everything correctly you should already see data for all of your tables:
Visual_Studio_SSAS_Tabular_with_Data
This is already the live-data that resides in your online database!

Congratulations! You are now connected online to your SSAS Tabular Database!

This approach can also be very useful if you are working with a backup of a SSAS Tabular database as it allows you to make online changes to the restored database and see all the data that exists in the database. Importing only the database project without this little hack would leave you with an empty database project which is very hard to work with if you need to create new calculations. Further, this also does not require you to reprocess the whole database which might not even be possible if you have no connection the the data sources underneath!

But before you get too much excited about this, there are some more things to keep in mind:

  • This is not officially supported by Microsoft
  • This was just experimental but proved (for me) to be very handy in some scenarios
  • Opening a SSAS Tabular Solution in Visual Studio sends and ALTER statement to the workspace database (in this case this is your productive database!) and updates the server with the metadata defined in your local .bim-file. If your server database changes frequently, this is probably not what you want as you would overwrite changes done by someone else recently. To work around this issue you would need to re-create/import your SSAS project every time before making any online changes to make sure you are always re-deploying the current state of the database when opening your local SSAS project.
  • I am not responsible for any data loss, damage or whatsoever!

If you want to use this approach to deploy hot-fixes and this happens frequently, you may also consider using a more professional approach for this – for example the BISM Normalizer Visual Studio Add-In which allows you to select the changes that you want to deploy to a target server, similar to schema compare for SQL Server.

Restoring a SSAS Tabular Model to Power Pivot

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It is a very common scenario to create a SSAS Tabular Model out of an Power Pivot Model contained in an Excel workbook. Microsoft even created an wizard (or actually a separate Visual Studio project) that supports you doing this. Even further, this process is also a major part of Microsoft’s strategy to cover Personal BI, Team BI and Corporate BI within one technology being xVelocity. This all works just fine but there may also be scenarios where you need to do it the other way round – converting a Tabular model to Power Pivot. Several use-cases come into my mind but I am sure that the most important one is to making data available offline for e.g. sales people to take it with them on their every day work. And in this blog post I will show how this can be done!

But before taking a closer look into how this can be accomplished, lets first see how the import from Power Pivot to SSAS Tabular works. To do this start SQL Server Profiler and connect to your tabular instance. Then create a new Tabular project in Visual Studio based on an existing Power Pivot workbook. At this point you will notice a lot of events happening on our SSAS Tabular server. The most important event for us is “Command End” with the EventSubclass “9 – restore”:
RestoreFromPowerPivot

SSAS actually restores a backup from a “Model.abf” backup file which is located in our project directory that we just created:
BackupExtractedFromPowerPivot

So far so good – but where does this file come from?

Well, the origin of the file has to be our Excel workbook that we imported. Knowing that all new office formats ending with “x” (.xlsx, .docx, …) are basically ZIP files, we can inspect our original Excel workbook by simply rename it to “.zip”. This allows us to browse the Excel file structure:
ExcelUnzipped

We will find a folder called “xl” which contains a sub-folder called “model”. This folder contains one item called “item.data”. If you take a closer look at the file size you may realize that both, the “Model.abf” file that we restored and the “item.data” file from our Excel workbook have the exact same size:
FileProperties

A Coincidence? Not really!

What happens behind the scenes when you import a Power Pivot model into SSAS Tabular is that this “item.data” file gets copied into your project directory and is renamed to “Model.abf” and then restored to the SSAS Tabular workspace instance by using an standard database restore.

Having this information probably makes you think: If it works in one direction, why wouldn’t it also work the other way round? And it does!

So here are the steps that you need to do in order to restore your SSAS Tabular backup into an Excel Power Pivot workbook:

  1. Create a backup of your SSAS Tabular database and rename it to “item.data”
  2. Create an empty Excel workbook and add a simple linked table to the Excel data model (which is actually Power Pivot).
    This is necessary to tell Excel that the workbook contains a Power Pivot model which has to be loaded once the file is opened.
  3. Close the Excel workbook and rename it from “MyFile.xlsx” to “MyFile.xlsx.zip”
  4. Open the .zip-file in Windows Explorer and locate the “\xl\model\”-folder
  5. Replace the “item.data” file with the file that you created in step 1.
  6. Rename the .zip-file back to “MyFile.xlsx”
  7. Open the Excel Workbook
  8. Voilá! You can now work with the data model as with any other Power Pivot model!

I tested this with a SSAS Tabular backup from SQL Server 2012 SP1 being restored to the streamed version of Excel from Office 365 with the latest version of Power Pivot. I assume that it also works with older versions but have not tested all combinations yet.

There are also some features that will not work, for example roles. If your Tabular database contains roles you will not be able to use this approach. Excel will complain that the Power Pivot model is broken. However, other Tabular features like partitions actually work with the little limitation that you cannot change them later on in the Power Pivot model or process them separately:
PowerPivotPartitions
Another thing to note here is that only up to 3 partitions are allowed, otherwise you will get the same error as for roles. I think this is related to the limitation of 3 partitions for SQL Server Analysis Services Standard Edition as Chris Webb described here.

Besides these obvious features there are also some other cool things that you can do in Tabular which are not possible in Power Pivot. Most (or actually all) of them are accessible only by using BIDS Helper – a great THANK YOU to the developers of BIDS Helper at this point!
BIDS Helper enables you to add classical multidimensional features also to Tabular models which is not possible using standard Visual Studio only. Those include:

  • DisplayFolders
  • Translations (metadata only)
  • Actions
  • …

I tested it for DisplayFolders and Actions and both are working also in Power Pivot after the backup was restored and I further assume that all the other things will also work just fine.
Simply keep in mind that Power Pivot is basically a fully featured Analysis Services instance running within Excel!

For my (and your) convenience I also created a little PowerShell script that does all the work:

  1. # Load the assembly with the ZipFile class
  2. [System.Reflection.Assembly]::LoadWithPartialName("System.IO.Compression.FileSystem") | Out-Null
  3. # Load the assembly to access Analysis Services
  4. [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.AnalysisServices") | Out-Null
  5. # Also install "Analysis Services PowerShell" according to http://technet.microsoft.com/en-us/library/hh213141.aspx
  6.  
  7. # INPUT-Variables, change these to match your environment
  8. $rootFolder = "D:\Test_PowerShell\"
  9. $emptyExcelFile = $rootFolder + "EmptyExcel.xlsx"
  10. $ssasServerName = "localhost\TAB2012"
  11. $ssasDatabaseName = "AdventureWorks"
  12.  
  13. # internal variables
  14. $newExcelFile = $rootFolder + $ssasDatabaseName + ".xlsx"
  15. $newExcelFileZip = $newExcelFile + ".zip"
  16. $unzipFolder = $rootFolder + "TEMP_ExcelUnzipped"
  17. $backupFile = $rootFolder + $ssasDatabaseName + ".abf"
  18. $itemDestination = $unzipFolder + "\xl\model\item.data"
  19.  
  20. # Copy the empty Excel file and rename it to ".zip"
  21. Copy-Item -Path $emptyExcelFile -Destination $newExcelFileZip
  22.  
  23. # Unzip the file using the ZipFile class
  24. [System.IO.Compression.ZipFile]::ExtractToDirectory($newExcelFileZip, $unzipFolder)
  25.  
  26. # Create a backup of the SSAS Tabular database
  27. Backup-ASDatabase -Server $ssasServerName -Name $ssasDatabaseName -BackupFile $backupFile -AllowOverwrite -ApplyCompression
  28.  
  29. # Copy the backup-file to our extracted Excel folder structure
  30. Copy-Item -Path $backupFile -Destination $itemDestination -Force
  31.  
  32. # Check if the target file exists and delete it
  33. if (Test-Path -Path $newExcelFile) { Remove-Item -Path $newExcelFile }
  34.  
  35. # Zip the folder-structure again using the ZipFile class and rename it to ".xlsx"
  36. [System.IO.Compression.ZipFile]::CreateFromDirectory($unzipFolder, $newExcelFile)
  37.  
  38. # Cleanup the unecessary files
  39. Remove-Item -Path $unzipFolder -Recurse
  40. Remove-Item -Path $backupFile
  41. Remove-Item -Path $newExcelFileZip

The last thing to mention here is that I don’t know if this is officially supported in any way by Microsoft – actually I am pretty sure it is not – so watch out what you are doing and don’t complain if something is not working as expected.