Apache Pinot

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

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

```{'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': {}}```

Hmm, I would have expected `rows` to be empty?

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

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

Because even if there is no row selected, aggregation still make sense. `SUM` of 0 record is `0.0`

For `MAX`, it is `-Infinity`; For `MIN`, it is `Infinity` etc.

In group-by though, woud we have empty results?

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

<@UDT7GFEG6> Is there any way to influence this default aggregation result ?

No, the default result is fixed for each aggregation

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

Would this change be desirable for Pinot ?

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

But we are trying to match the standard SQL behavior

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

True, currently we only support explicit filtering on null values

We don't support null values in the query responses yet

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 ?

Thanks <@UDT7GFEG6> :slightly_smiling_face:

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

<@UDT7GFEG6> And empty group aggregation results ?