Errors in the OLAP storage engine: A duplicate attribute key has been found when processing:

While processing a dimension, processing got failed and shown the below warning as well.

Errors in the OLAP storage engine: A duplicate attribute key has been found when processing:..

But when I checked the values of the mentioned attribute, there were no duplicate values. But the relevant column data type is INT and it has a value as NULL.

When I checked the dimension attribute key column properties, NullProcessing property is set to Automatic.

Actually this is causing the above error message since during the processing, NULL values are converted to 0 and we already have an attribute value as 0.

Same issue can happen for the string data types having blank value as well.

To fix this we can replace NULL values with the relevant value in the Data Source View of the Cube or replace it in the Data Warehouse using the ETL. Best way to do is to change it in the Data Warehouse.

Below link contains more details about this issue as well.

http://blog.oraylis.de/2013/08/a-duplicate-attribute-key-has-been-found-during-processing-revisited/

Error message when trying to open SQL Server Configuration Manager in SQL Server: "Cannot connect to WMI provider. You do not have permission or the server is unreachable"

We had an issue that SQL Server Analysis Server is not getting started and cannot connect to the SQL Server Configuration Manager as well. While trying to connect to the SQL Server Configuration Manager, got the below error message.

Cannot connect to WMI provider. You do not have permission or the server is unreachable. Note that you can only manage SQL Server 2005 and later servers with SQL Server Configuration Manager.

According to the below Microsoft support link, it says that the WMI Provider file is removed when the SQL Server is uninstalled.

https://support.microsoft.com/en-us/kb/956013

But in my case that is not the reason, since we did not do any uninstall. Possible reason could be that file is corrupted.

Before following the steps mentioned in the link, you can just try the below steps.

• Stop the Analysis Service service
• Restart the Windows Management Instrumentation service
• Then try to restart the SQL Server Analysis Service service.
• Check whether the SQL Server Analysis Service service is getting started, if not follow the steps mentioned in the link as below.

• open a command prompt, type the following command, and then press ENTER:
• mofcomp "%programfiles(x86)%\Microsoft SQL Server\number\Shared\sqlmgmproviderxpsp2up.mof"
• Note For this command to succeed, the Sqlmgmproviderxpsp2up.mof file must be present in the %programfiles(x86)%\Microsoft SQL Server\number\Shared folder.
• 
  
• The value of number depends on the version of SQL Server:nnn
  
  Microsoft SQL Server 2012 - 110
  
  Microsoft SQL Server 2008 R2 - 100
  Microsoft SQL Server 2008 - 100
  Microsoft SQL Server 2005 - 90

• Then restart the Windows Management Instrumentation service.
• After that restart the SQL Server Analysis Service service as well.

This should fix both the issues mentioned above.

How to prevent first time cube access performance issue, after a cube refresh with Dynamic Security...

Recently we faced an issue that, after a cube refresh there is a performance issue while accessing the cube. This happens since the dynamic security was implemented.
This performance issue can be prevented by building cache for each user.

SSIS package was implemented to build the cache. In the package the approach used was to execute the create cache mdx command using each user id.
You can connect to the SSAS cube with different users by using the EffectiveUserName property in the Connection String.

The structure of the package is as shown below

Steps:

• Create four variables as shown below. 

• OLAP_ConnString is the value used as the connection string for SSAS cube. It includes the user name by using the EffectiveUserName property.
• UserNames variable is used to get the list of users. 
• Each user is assigned to UserName variable in the Foreach Loop Container.

• Execute SQL Task us used with in the Foreach Loop Container use to create the cache using the MDX command. Since Effective User Name property is set using the UserName variable, the MDX command is executed for the particular user. That means the cache was created for that user.

After a cube refresh, we need to execute this package and it will prevent the first time access performance issue.

Problems when trying to get changed records from...

The SSIS Package was configured to get only the net changes by applying the CDC processing mode as Net in the CDC Source.
But when the SSIS package was executed, got the below error message.
"Problems when trying to get changed records from dbo_testcdc. Reason - Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding..".

The issue was fixed by using the below steps.

• Right click on the CDC Source and select Properties.
• In the properties window find the Command Timeout and change it to 0. Default value of this property is 30.
• Save the package and execute it. It should run without any issue.

CDC Failed when changing the database or the CDC State table in SSIS Package...

Recently we faced that the SSIS packages got failed which use CDC, due to a validation issue when the data source is pointing to a different database or the CDC State table is pointing to a different one.

The solution is to set the Delay Validation property to True.
But I found that sometimes this is not enough in the package level and need to set it in the Data Flow and the set ValidateExternalMetaData to False in the CDC Source as well.

Hope this is helpful for you as well.

Rank SSAS Cube data based on a filtered data set using MDX...

I explained how we can use MDX ranking in the below two posts.
MDX Rank and Advanced MDX Ranking.

But the queries given in those two posts will not work if you are filtering data using a dimension which is used for ranking and data is filtered using a sub cube. In such a case it will rank the data using the all the data set and filter it after that. If you filter it in the Where statement, Rank will work fine. But the issue is in this scenario you cannot use it, since the same dimension attribute is already used in the query.

To avoid this, we need to only use the filtered dimension members in the ranking calculation as well.
The sample query is as below. In that, ranking needs to be done for the selected stores and the used parameter is paramStores.

WITH
MEMBER [Measures].[RankSales] AS
RANK(([Store—Region_Store].CurrentMember,[Store—Region].CurrentMember,[Item—Department].CurrentMember),
ORDER(({STRTOSET(@paramStores)*[Store—Region].CurrentMember*[Item—Department].CurrentMember}),
[Measures].[Sales], BDESC))

SELECT {[Measures].[RankSales]} ON COLUMNS,
{STRTOSET(@paramStores)*[Item—Department].[Department].MEMBERS} ON ROWS
FROM  [Sales]

The output will be ranked only based on the available values in the paramStores parameter.

Adding additional dimension attribute value in MDX query...

Depending on the requirements, sometimes it is necessary to do some categorizations which does not included in the dimension data. In such scenarios we may have to add a dimension attribute which currently does not exists with the dimension data.
We can do it in the MDX query as below.

WITH

 MEMBER [DimBranch].[Branch].[Dummy] AS

   '0',

   SOLVE_ORDER = 0

 SELECT

 {[Measures].[CONTRIBUTION USECASE]} ON COLUMNS,

 NON EMPTY Union(

   [DimBranch].[Branch].Members,

   {[Branch].[Dummy]}) ON ROWS

 FROM [Sales]


You can set the measure value based on the required logic.