Hello @tintin,
Yes that was clear.
But in every instance you only have two series.
So I believe that if you wrote the following three points
Measurement,DeviceID=D1,SensorID=T1 Field1=1
Measurement,DeviceID=D1,SensorID=T1 Field2=1
Measurement,DeviceID=D1,SensorID=T1 Field3=1
Then your cardinality would equal 3.
Try SHOW FIELD KEY EXACT CARDINALITY instead.
1.x doesn’t include field keys in the series key, so in the cardinality data, it doesn’t include the field key. However… field keys are actually part of the series key (on the storage level)
Yah that’s confusing. But this discrepancy was fixed in 2.x. The different commands were used to help users dive into their runaway cardinality problems, but now there are better solutions:
