Best practice to incrementally materialize metrics with different time grains

I am wondering on how to set up incremental materialization of metrics that have different time grains.
Let’s say I have a metric that has day, month and year grains. Every day I want to materialize its values into two different tables: one with daily grain, one with monthly grain.
Daily table materialization can probably be set up in a way that I always calculate the data for the previous full day and I never really have to merge anything, just insert new rows one day at a time.
But what about the monthly table materialization? I expect the table to return the “last known value” for the current month (e.g. on 16th of March 2023 I want to show the value calculated based on 2023 March 1-15).

I have variables “data_interval_start” and “data_interval_end” that I get from Airflow, they correspond to the run start timestamp and run start timestamp + interval respectively. I guess I can work with these to recalculate a suitable amount of data every time, but I’m wondering what is the best approach to do it.

Detailed example to work with

Metric definition:

  - name: orders_finished
    label: Orders Finished
    description: "Number of orders finished"
    model: ref('schema_name')
    calculation_method: count_distinct
    expression: order_id
    timestamp: created
    time_grains: [day, month, year]
      - field: state
        operator: '='
        value: "'finished'"
      - city_id

Model that materializes the metric:

        materialized ="incremental",
        incremental_strategy ="merge",
        unique_key =["city_id", "date_day"],
        partition_by ="date_day",
        schema = "schema_name"

select * 
from {{ metrics.calculate(
) }}

A macro would help here and then pass the date grain as a parameter so you can keep the query itself controlled and applied in different models - and then honestly I would have a job that uses tags to select based on the grain you want. That’s the easiest way to do it otherwise you get into the scenario of an incremental load where you are checking it every time in your incremental logic to see if a new period has finished.

run the daily model daily, weekly weekly and monthly monthly. Then likely don’t even need to make it incremental adn worry. You can just refresh the whole thing.

Note: @Garrett McClintock (Heap) originally posted this reply in Slack. It might not have transferred perfectly.

What if I want to run the monthly model on daily basis? The last month would effectively contain “month to date” and would be updated every day.