I have a view which calculates rolling sum taking in value form previous row based on `PARTITION BY` clause, and I need to indicate one field Im using in PARTITION BY clause can have nulls in them.

```
sum(s."QuantityChange") OVER (PARTITION BY s."LocationId", s."PartId", s."SupplierFacilityId" ORDER BY s."DueDate" ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS "RunningSum"
```

sometimes `SupplierFacilityId` is null and that's fine, it should still be included in the sum() calculation.

Is this possible with Postgres?