@User @User I am looking to support nulls in aggregates (a common use case for us). Is there a place where I can get prior thoughts and research, and potential starting ideas?

@User there has been some work done with null support in the past, perhaps we can start from where that discussion ended cc @User @User

@User Does putting a null filter work for your use case? E.g.

SELECT SUM(col) FROM table WHERE col IS NOT NULL

?

Could we use a Sentinel value to represent NULL, per data type?

That is doable, but can introduce some backward incompatibility. Also, the per-value if check is not avoided. A better solution could be applying the null value bitmap for each aggregate before scanning the values. Currently we can only apply null value bitmap on query level, not on aggregate level

Jackie, you mean we can apply bitmap at filter phase not aggregation phase?

I think we can apply it inside the aggregation operator itself?

we need to think about that a bit

I mean we need to apply bitmap at aggregation phase in order to support multiple aggregations with different null bitmap

@User You mean add a bitmap to ProjectionBlock? That would be sweet

yes, it should be a bitmap from the projectionblock

OK, this makes sense. Let me investigate this