Forum Discussion
Best practices for working with star model?
Continued ContributorAnonymous are you trying to load your data mart in Power BI using import feature? if yes then the error could be because you have limited resources on that machine e.g. Memory.
Try to load it using DirectQuery if you are reading it directly from RDBMS or use direct connection if you are using OLAP cubes.
Secondly, as best practise in star schema you should not combine all the facts which are on different grain levels into one fact table, this is violation of basic star schema rules. If you design is correct, star shema should not be an issue to load the data.
We can help you more if you elaborate your question with examples and screen shots of your model.
Regards
Harris
HarrisMalik and ankitpatira thank for your help.
My machine has 8gb of ram and processor i7 3.6 GHz for sure the reason for the slowness in charge is not because of my computer, so that other programs like QlikView and tableu can carry the same DW no problem and fast way.
Here is a picture of how is my star schema, sorry the image resolution but it was what I could do.
As can also be noted there are several tables without relationships, I had to do this because as I was informed concatenei all my tables facts to form a single Fact table.In short, I have 11 tables Facts and over 10 tables dimensions.
I get this data from a DW that is in a Sybase database, and is not a cube and make the load via SQL Query using an ODBC driver, following an image to illustrate.
- ankitpatira
Community Champion
Anonymous If you've such large number of tables to work with each having PK FK relations then DirectQuery is the best option. When Powerbi desktop import tables it doesn't look at your PK, FK relations but tries to determine relations on its own based on few rules such as it uses field names to determine relations. For example P_ID in one table will be linked with P_ID in other table. So then it would try and determine as many relations it can and leave other blank or inactive (inactive due cardinality conflicts).
If you absolutely needs to use Import then I would suggest create relations between each tables manually via relationship editor.
As you can see in the last picture I let disable the automatic creation of relationships between the tables at the time of loading, the dimensions of the relationship to the fact table were done manually after loading the data
Sorry I forgot to mention, follows a picture of my options loads of power bi, left virtually disabled all load resources so there is not much processing during the load in order to optimize the load is in Portuguese but the order of option are the same as those in any other language
thanks again!!!!!!!!
