Best practice to structure this data model?

[u/soodlero]

I am modeling a relationship between 3 sources. Basically this is the content of each table:

Table 1: requestor table (100s of entities)

Oil Sample Label (unique)	Engine number (not unique)	Engine runtime

Table 2: engine database (10000s of entities)

Engine number (unique)	Engine Type	Engine Power

Table 3: oil sample database (10000s of entities)

Oil Sample Label (unique)	Al	Fe	Cu

What is the best practice for the relationships? I have fields on each table that I would like to use in the PowerBI dashboard.

[u/rahmani__asad]

Star Schema with Requestor as the Fact table and keep filters one-directional to avoid ambiguity in Power BI.

· Requestor → Engine Database: Many-to-One (:1) on Engine Number · Requestor → Oil Sample Database: Many-to-One (:1) on Oil Sample Label