Misc Power BI Questions

[brs09j]

1) If theres a relationship bewtween Table A and Table B then you can select fields from both tables to create a visualization. Without the relationship this does NOT work. What I really want to know here is, does the relationship chosen between the tables matter? As in, what colums on each table are joined or is a relationship a relationship (not talking about joining unrelated columns here). I understand filters only move from the one side to the many side unless bidirectional filtering is on.

2) The star schema can't always be followed. In this event, does that mean all tables without dates on them can not be analyzed with time intelligence? Or do tables have to be joined/merged? I know how to create my own dates table.

3) If I join a table with dates to my own created date table, when I make a visualization which table's date fields should I use? Does it matter?

Thanks.

[Greg_Deckler · Accepted solution]

So, for 1, the first part is only partially true, you can use the disconnected table trick, which essentially is the creation of a measure that effectively serves as a bridge between the two disconnected tables. In terms of whether the fields in a relationship matter or not, no, a relationship is a relationship but it will definitely matter in terms of your data model, you want to relate things properly according to what you are trying to achieve.

For 2, no, even if you do not have a star schema, as long as the directions of your relationships are configured properly, you could still use time intelligence in a non-star schema data model. You can create very complex data models in Power BI but often you have to pay close attention to filter direction.

For 3, I assume that you mean "create a relationship" versus "join". In this case, it depends. For example, if you have a data model like the following:

Table 1 <--- Date Table --> Table 2

And you are trying to create a visualization that uses data from Table 1 and Table 2 then you would want to use the Date field from your Date Table as there is no filter direction that essentially relates Table 2 to Table 1.