I’ve really been working hard to understand how this data modeling should work, but there are a few things I I’m having a hard time understanding
Here’s the Link I am currently studying. https://docs.oracle.com/en/cloud/paas/analytics-cloud/acsmd/plan-semantic-model.html#GUID-99680D14-8751-4E53-81E6-EE704DFB3EF0
Here are some things I DO understand now
- Joins are all created with the arrow pointing to the ‘many’ side of the join
- Models should be created with a star or snowflake pattern. (I don’t really understand the snowflake model).
- Hierarchies are created with logical dimensions if you want to drill down
- I’ve created a calendar dimension table for drilling
Here are my questions that I don’t understand.
- How to determine when to use left join in the BMM
- How to determine cardinality in the BMM (these two questions are confusing me because of the way they are joined in the physical layer.)
- How to organize the tables. The link above says tables are to be conformed by being combined into one view. Does this mean that I should write a view combining them and then import that metadata? Or does it mean rather that the tables are combined by dragging into one logical table and joined that way? FYI I do understand this doesn’t mean combining all of the tables, but just the related details that would prevent making the star model work.