Physical Date table vs Code

[Anonymous]

When deciding on a date table for a report is it recommended to import a physical table from the warehouse or generate one via code? Does the generated table get persisted, or does the report have to generate it each time its loaded? Does one perform better than the other or does it make no difference?

[Anonymous]

Thanks @amitchandak. I also did a test where I created 2 blank reports, loaded 1 with a 45,000 row date table from the warehouse, and in the other created a 45,000 date table from code. I then put a date slicer on each and loaded a table with the dates and looked at the Performance Analyzer. Every test between the 2 was less than 100ms apart, and the slowest test was just 400ms so you really can't even tell any performance difference. I also tool a look at the report file sizes, and the code version was 3x the size of the one loaded from the database, but again the files are so small that the difference may even be something else (637kb vs 1,827kb respectively)

[amitchandak · Accepted solution]

@Anonymous , Both will take space, Refresh will depend on what changes are required, even if you bring a DB table that also need to refreshed.

I feel power BI date table give lot of flexibility. But if there is one in a database all set, why to create again in power bi, just mark it as the date table.