What programming languages should a MS BI specialist know?
My job has slowly been evolving from data analyst/report writer type work into more of a BI specialist role over time. The vast bulk of the "programming" that I do is TSQL with small bits of VB script, powershell and even VBA in rare cases. Obviously I can use SSAS (to some extent), SSRS, and SSIS. What other programming languages do BI specialists need to be on top of? I've heard that BIML, R and C# (eg for CLR) can be useful. It seems that SharePoint development is also a BI flavor of the month. I'm worried though, that breadth of knowledge can come at the expense of depth. I also believe that a little knowledge is a dangerous thing.
So much depends on the sort of BI role you want to get into. DAX and MDX will help a lot with the SQL Server/Microsoft ecosystem, but if you are getting into more of the Data Science end then R and Python are valuable tools. R by itself is quite dry but there are so many useful add-ins now. Read [anything on Simple-Talk by Sergei Dumnov] to get a flavour of the simple things you can do with R in combination with SQL Server and
ASP.NET MVC. :
It seriously depends on what you're doing as BI specialist. Saying that brings to mind people working with cubes which means you need to learn MDX. If your work is primarily around data loading, then T-SQL, PowerShell, VBScript, SSIS, BIML. If you're working in SSRS, T-SQL is all I can think of.