[Basic Question] the measurement deletion still keep the old field name

Hi, Experts

as for the deletion of influxdb measurements, if i want to remove some fields from existing measurement in order to make the measurement looks simple and clean. but it seems not possible

> insert test,type="b" val=2 1504225728000123456
> select * from test
name: test
time                           caseAuthor caseName caseResult type val value
----                           ---------- -------- ---------- ---- --- -----
2017-09-01T00:28:48.000123456Z                                "b"  2   
> 

the old field name caseName and caseAuthor still there, I guess maybe i did not delete correctly by
Drop series from test

anyone could explain that to me

thanks
/Yijun

I think you might need to drop a shard. Others could confirm.

thanks for your help, Yes, probably del Shard could help to remove all the information,
but not sure whether there is other way to cleanuo without Shard operation