Mstr 7.2.X compatible with Star-Schema ??

[JoaoCruz]

Many people said to me that Microstrategy 7.2.X don't work well with a Star-Schema model.
To ask my doubts i research in Mstr support site and found the follow lines :

Question : "What types of schemas does MicroStrategy 7.x support? Is there a preferred schema? Does MicroStrategy 7.x support star schemas?

Answer:
MicroStrategy 7.x supports almost all schemas other than a consolidated star schema with level indicators. MicroStrategy does not recommend the use of consolidated star schemas since they limit functionally and are maintenance-intensive. "

Defects and Enhancements addressed in MicroStrategy 7i-7.2
MicroStrategy SQL Generation Engine(Product) 136745(log ID) 7.1.2(versão reportada) 123742(case) - Incorrect results with star schema and Partitioning when the attribute display is not the ID (last join to lookup table causes a partial Cartesian join)


I need your help...
I'll wish to know what your experience tell you about this "relationship" Mstr7.2.X - Star-Schema ...
Many Thanks..

 

[mstrNate]

I'm not sure what MicroStrategy means when they talk about a consolidated star schema with level indicators. I can tell you that MicroStrategy has typically preferred a more normalized schema where you split out the dimensional attributes across multiple lookup tables instead of keeping them in one table like Ralph Kimball recommends. I think that generalization can apply to most of the recent versions of their software (6.x and 7.x).

Having a denormalized star schema can potentially contribute to double (triple etc.) counting in MicroStrategy. Now, they might be able to do this, but the last few projects I've worked on have all used a more normalized schema. If the physical database was denormalized, then they implemented views on top to normalize the table out for MicroStrategy's SQL engine. Unfortunately, I can't give you an example from 7.2.x because I haven't tried it yet. So I don't know if they've gotten better at it or not.

Nate

 

[mstrNate]

Here is a technote on the MicroStrategy techsupport site. It talks about how MicroStrategy 7.x handles Star Schemas as well as other data modeling issues one might have. Just came out today.

Nate

TN5200-7X0-0123

 

[paulmaric]

As the tech note explains, MicroStrategy works well with snowflake or star schemas. An issue may arise if any aggregation is in place, and the lookup table for the attribute that is aggregated up to doesn't uniquely identify the values of that attribut (e.g. in their example, Month is not uniquely defined in the LU_TIME table -- Day is).

Star schemas with level indicators is still not supported.