Merging tables results to evaluating more rows

[Dimitris_K]

Greetings all!

I am new to Power BI and still trying to figure out some things.
I imported 4 table views as suggested (specific columns, and DateTime converted to Date), and then merged them together. Suppose I have tables A,B,C and D.
Table A is the Users table.

Table B contains the MAX(date) per UserId, which results in importing far less rows than the original table isn my DB.

Table C like table B, but from another table in DB.

Table D contains only a specific trait for each user (one per user).

I merged into A with LEFT OUTER joins B,C, and D. So it all should be 1-to-1 or 1-to-0.

When I merge them, expand the columns and keep the ones I require, then press "Close and Apply", it does create a merged table with number of rows=rows of table A.

However, during import it calculates rows of all four tables as imported, which results into taking a lot time when importing or refreshing the report.

Am I doing something wrong, and can I make it not calculate excessive rows? Or do I have to import an amalgam of these tables directly from my DB?

Thank you all in advance for your replies and time!

Kind regards,

Dimitris

[v-shex-msft]

HI @Dimitris_K,

Actually, I also not found any effective solutions to improve performance of your scenario.

Maybe you can try to add new blank query to store records which merged and reference from original tables, then turn off original queries' loading option.

In addition, you can try to direct use advanced t-sql query to get merged table.(I think load one table will more effective than load and calculate on multiple tables)

Regards,

Xiaoxin Sheng

[Dimitris_K]

Hi @v-shex-msft

Thank you for your answer.

I have tried to import one table that is already merged, but I was not sure if this would be more efficient, performance-wise, than importing views of tables and then merging them.

Regards,

Dimitris Karmiris