It's my understanding there are two approaches to display related data via the column list. You can either use the filter function for example I have a contacts table and a phone table on the contact detail screen I have a column list displaying the related phone numbers using the following data source =FILTER(Phone,"Phone[Contact]=%",$[InputRow])
Another solution I tried was at the table level of contacts I created a column PhoneNumbers using =FILTER(Phone,"Phone[Contacts]=%",THISROW()), now that the column displays a list of the related phone numbers I can then use that column as my data source for the column list. I updated the column list data source formula to =$[InputRow][PhoneNumbers]
Both approaches work and display the correct set of related records however I'm curious which is the better approach. Is there a performance gain on one approach vs the other.
In regards to performance, there is no notable difference, as it's the same calculation being evaluated in both scenarios (just one is happening in the tables while the other is in the app). And as you stated, both solutions would work and display the desired data.
However, for a best practice, I would recommend writing your filter formula in the column of the table (Format the column to that formula), and then call that value for the list data source in the app, as you did in your example.
By putting the formulas in the table, it can make it easier to locate and edit formulas, and you can also more easily call the values in the app in different locations, without having to rewrite a filter formula each time.
I hope that is helpful! Let us know if you have any further questions on this.
