The API returns ` Infinity ` and the Web UI shows the same

Question

Mayank · Answer

Can you paste the returned json

Jonathan Meyer · Answer

Sure

Mayank · Answer

If no rows selected why is there even a value being returned

Jonathan Meyer · Answer

``` exceptions minConsumingFreshnessTimeMs 0 numConsumingSegmentsQueried 0 numDocsScanned 0 numEntriesScannedInFilter 2 numEntriesScannedPostFilter 0 numGroupsLimitReached False numSegmentsMatched 0 numSegmentsProcessed 2 numSegmentsQueried 2 numServersQueried 1 numServersResponded 1 resultTable dataSchema columnDataTypes DOUBLE columnNames aggregated value rows Infinity segmentStatistics timeUsedMs 6 totalDocs 894 traceInfo ```

Mayank · Answer

Hmm I would have expected `rows` to be empty

Mayank · Answer

Given `numDocsScanned` = 0

Mayank · Answer

< Jackie>

Jonathan Meyer · Answer

Yeah sounds more logical to me too I can confirm that querying without the aggregation really yields 0 documents

Jackie · Answer

I assume this is a `max ` aggregation

Jonathan Meyer · Answer

< Jackie> Nope it is `AVG`

Jackie · Answer

For aggregation when there is no record selected Pinot returns the default aggregation result

Mayank · Answer

Why not empty

Jonathan Meyer · Answer

And `SUM` returns `0 0`

Jackie · Answer

Because even if there is no row selected aggregation still make sense `SUM` of 0 record is `0 0`

Jackie · Answer

For `MAX` it is ` Infinity` For `MIN` it is `Infinity` etc

Mayank · Answer

In group by though woud we have empty results

Jackie · Answer

Yes because there is no group exists

Mayank · Answer

If you think of output as a table then we should return empty row for aggr only

Jonathan Meyer · Answer

< Jackie> Is there any way to influence this default aggregation result

Jackie · Answer

No the default result is fixed for each aggregation

Jackie · Answer

Seems the standard SQL behavior returns `null` in case there is no record selected

Jonathan Meyer · Answer

Would this change be desirable for Pinot

Jackie · Answer

Pinot does not support real `null` yet and `null` is always represented as a default value as of now

Jackie · Answer

But we are trying to match the standard SQL behavior

Jonathan Meyer · Answer

Even with <https docs pinot apache org developers advanced null value support> I know according to docs that it s still a partial support as in there s no interaction with aggregations etc but it s possible to efficiently filter null values and not mix them with real values e g 0 0 right Edit Updated link

Jackie · Answer

True currently we only support explicit filtering on null values

Jackie · Answer

We don t support null values in the query responses yet

Jonathan Meyer · Answer

Yep okay So AVG with null values without explicit filtering will just result in the values being considered as their default e g 0 0 value in the aggregation

Jackie · Answer

Yes

Jonathan Meyer · Answer

Thanks < Jackie> slightly smiling face

Jonathan Meyer · Answer

And < Mayank>

Jackie · Answer

The default default null values is documented here <https docs pinot apache org basics components schema>

Jonathan Meyer · Answer

< Jackie> And empty group aggregation results