Why is the following query is returning the wrong ...
# troubleshootingr
robert zych
09/29/2022, 4:03 AMWhy is the following query is returning the wrong result? The cardinality of d1 is 3K and the cardinality of d2 is 200k. numSegmentsMatched is 1. numGroupsLimitReached is false.
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select d1, d2, max(metric) as max_metric
from t
where datetrunc('DAY', created_at_epoch_ms) = 1660867200000
group by d1, d2
order by max_metric desc
limit 1m
Mayank
09/29/2022, 4:06 AM
How did you validate it is wrong?
r
robert zych
09/29/2022, 4:30 AMI first started with grouping by one dimension at a time and got the same max_metric value which is much higher than the value returned when grouping by both.
robert zych
09/29/2022, 4:31 AMI can get the expected result if I filter by one dimension and group by the other.
m
Mayank
09/29/2022, 4:33 AM
Grouping by one is different from grouping by two and not expected to match
r
robert zych
09/29/2022, 5:07 AMI agree in general. But given I know which combination of dimensions yields the max, grouping by both should work.
m
Mayank
09/29/2022, 2:39 PM
If you are convinced it is a bug then please file a GH issue with a test case.
r
robert zych
09/29/2022, 4:04 PMThis isn't a critical issue yet. If it becomes critical then I'll follow up with you about how to submit a GH issue.