Thursday, January 10, 2019

Create a New Partition on existing multi-dimensional SSAS cube.

Below is a process that I follow every year to create a partition in existing multi-dimensional SSAS cubes that I maintain.

  • Log in to the SQL Server Analysis Services server using SQL server Management Studio as shown below.

  • Expand the Databases by clicking on the + sign.  Choose the database you want to create the partition for.  
  • Expand the Cubes  and expand the Cube that you want to partition. Expand the MeasureGroup and expand the Measure Groups – You can see the Partitions folder there.  Expand the Partitions folder to see the existing partitions as shown below.

  • Right Click on the Partitions folder and click on New Partition as shown below:

  • Partitions wizard opens as shown below.  Click on Next

  • Choose the MeasureGroup and table as shown below.  You must choose at least one table to proceed further. 

  • Click Next

  • You need to restrict rows in this partition by providing a query.  Tick the specify a query to restrict rows in the below screen.  

  • Make sure your query selects rows that are included only in this partition.  I usually use the where condition that selects data in a year.  
  • For example select * from [dbo].[cubeExample]  WHERE LEFT([DateKey],4) = '2019'  This query gives data only for 2019.

Click on Check after providing the query to validate the syntax as shown below.

  • If the Syntax check was successful, you will get a success message as shown below.

  • If the Syntax Check was not successful, it gives an error.  An example error is shown below.

  • Fix the error and recheck the Syntax.  Click Next.  you may be asked for  a UserName and Password as shown below.

  • Choose Your Processing Location and Storage Location as shown below and click Next

  • Choose the Name of the partition on the Next screen and also the Aggregation options as shown below and then click Finish

Tips that I learnt:

  1. Ensure that you take a backup of the Cube database before creating the partition.
  2. Ensure that you have the permissions to create the Partitions.  Also ensure that the username you use is a generic username and not your own username 
  3. Ensure that you have a look at the query for the previous partitions.  Best approach is to copy the query for the partition for the previous year and use that as a starting point.

Tuesday, January 08, 2019

Power BI Did you know - Series 2 (Add Refresh Date )

Did you know that you can add a refresh date to indicate when your data has been last refreshed ?

Below are the steps to do this.

  • Open the report in Power BI Desktop
  • Go to Edit Queries from the Home ribbon as shown below

  • From the Power Query editor, choose the table where you would like to add the refresh date and click on Advance Editor as shown below

  • Add the below code before the in statement 
 #"Added Refresh Date" = Table.AddColumn(#"Renamed Columns", "Refresh Date", each DateTimeZone.FixedUtcNow(), type datetimezone)

  • Replace "Renamed Columns" from the above code to the name that is mentioned just above the line as shown below

For example if the below code is in the Advanced Editor, the "Removed Columns" in the step need to replace the "Renamed Columns" as shown below

    Source = Sql.Databases("localhost"),
    table1 = Source{[Name="table1"]}[Data],
    dbo_table = table1 {[Schema="dbo",Item="table"]}[Data],
    #"Removed Columns" = Table.RemoveColumns(dbo_table,{"col2", "col4", "col6"}),
    #"Added Refresh Date" = Table.AddColumn(#"Removed Columns", "Refresh Date", each DateTimeZone.FixedUtcNow(), type datetimezone)
    #"Added Refresh Date"

  • This will create a new column named Refresh Date in the table.
  • Close and Apply changes.

  • Now create a new measure, in order to add the last refresh date to the report 
  • An example code for the new measure could be as below

Footer = CONCATENATE("Last Refreshed " , MAX(Schedule[Refresh Date]))

Use a card visual to display the measure as shown below

There you go, you have the last refreshed date in your report

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