ASP.NET Core : get data from SQL Server of from SSAS OLAP Cube?

Question

I have a problem with an application which encompasses an SSAS project, with an OLAP cube, and a client project using ASP.NET Core and Blazor WebAssembly, and a SSRS project.

The ASP.NET Core app retrieves reports from the SSRS server, but the report parameters are written in C# and Blazor; and the problem I have is about how to get available values for these parameters.

For example, if a filter is about anesthesists, I want to display in a combobox all the anesthesists names, but from where do I get this information?

I have 2 choices: either from the OLAP cube, using the AdoMdClientNetCore Visual Studio extension, or from the source database in SQL Server.

I would like to know if there are some good practices concerning this subject; I googled here and there but without relevant results.

Answer 1

I would recommend to get data from SSAS. Reasons for this:

1. Working structure of your project - Client project <-> SSRS <-> SSAS <-> Some DB. And Some DB datasource is beyong the scope of the project. SSAS acts as a single point of contact with Some DB, if the Client App will access the DB - it will create another contact point to the DB. This extra contact point has to be configured, maintained etc.
2. SSAS updates its data, reading from its data sources, in timely batch manner during so called "Processing" jobs, unless you use special ROLAP mode. This means some delay in information passing from DB to SSAS. Report gets data from SSAS, so, reading directly from DB could bring in inconsistency some rare cases.
3. Separation of concern. SSAS accesses DB with some queries. If the Client App accesses the DB as well, modifications made to SSAS have to be transferred to the Client App, complicating development and support of the solution.