Hi,

I'm wondering what the best practices are for implementing logic changes that are time-sensitive.

For example, let's say that through May-2019 the "amount" is calculated as ((Column A + Column B) / 2), and starting June-2019 the amount should be ((Column A + Column B + Column C) / 2), or any other logic that only takes effect starting a certain month without affecting prior months.

Apart from creating a new table and a new transform pipeline, is there a way to reference the month in the formulas (or any other way in the transform pipeline), so that the same table can still be used for all periods?

Thanks,

Guy

You might be able to use some variation of the CurrentMonth() function.  For example, If(CurrentMonth IN(Jan-May),formula1,formula2).  Obviously, the syntax will need to be worked out, and you might need a helper column or two (i.e. do the CurrentMonth function in its own column, then reference that column in the If statement), but I think that should get you in the right direction.

Hi @Guy Beletsky,

we did earlier what @James Funk proposed but we came to a point were the formulas got very messy after a while and not anymore maintainable.

We switched to work with versions of tables:

Downside is that you need to be aware that the formulas are changing depending on the version you are currently looking at. Hence, from one month to the other formulas might change. At the beginning it was also confusing but as soon as we got used to it, it is better maintainable than the =currentdate forumals.

It's a good point.  If the formulas are simple enough, then maybe just using formulas will work.  But if not, then maintainability definitely comes into play, and versioning might be the best solution.  Ultimately, the "best practice" is what works for you in your specific situation.  No one solution will solve everything.

absolutely right. At the beginning we had to change 2-3 formulas, then it was perfect to do via formulas. Over the course of multiple months and many changes, we then switched to versioning.

This might be a good rule of thumb.... few changes -> via formulas, many changes -> versioning.

Thanks guys, this is helpful. And I agree that using formulas for this is only good if it doesn't make the logic convoluted and hard to follow/maintain.

Looking at the "Create Version" feature, it looks pretty convenient to use - if you see the "Remove Version" button clickable, it means you have multiple versions, and by hovering over this button on various months you can figure out what periods the versions are for.

Thanks!

You might want to take a look at Replacing a Data Source that covers a way of doing this without using versioning.