juffin (http://www.cognoise.com/index.php?action=profile;u=86713) wrote in a personal message:
QuoteHi MFGF
I have seen some posts on Star schema on FM.But still I am not clear on this. Please can you guide me on this.
Can we really create a star schema in FM if fact table is not in database?
As per my understanding fact table should have foreign keys and all the measures. But if there is no Fact table created in database
is it possible to create a Fact table in FM. I tried to create a Fact QS (data source QS) in FM by dragging and dropping all keys and measures. But as their are no joins it ended in error.
Thanks in advance.
Regards
Jf
Framework Manager is not a tool that creates physical schemas in a database. For this you would need an ETL tool such as DataStage/Data Manager/SSIS/Informatica etc. If you are pointing at a "normalised" database from FM, you can model these tables and their relationships in a foundation layer, then build model query subjects in a layer above this that represent the structures you would find in a star schema database. It's not creating anything physical in the database to support this, though, so when you query a single "table" (query subject) from this layer, the underlying query might span several physical tables in your database.
Hopefully you can see that this is less-than-optimal. The ideal situation is to have physical star schema tables in your database, which means you have little modelling to do and the generated queries are simple and elegant. If you do not have the luxury of doing this, you can make your data look like star schemas in FM, but queries will likely be big, ugly and slow.
Cheers!
MF.