the NOT operator works on any role of a time series

If a time series has more than one role, the NOT operator might not work correctly.

Example:
Neither

curl "http://127.0.0.1:8000/search/?has_role=~OpenAQ,UVK,ECCC,rodrigoseguel@uchile.cl,KU,EBAS"

nor

curl "http://127.0.0.1:8000/search/?has_role=~OpenAQ,UVK,ECCC,rodrigoseguel@uchile.cl,KU,Dagmar%20Kubistin"

works, because the first role of this special time series fits only the first WHERE clause, while its second role only fits the second WHERE clause.

Only a combination of both roles will ensure, that this time series is not selected:

curl "http://127.0.0.1:8000/search/?has_role=~OpenAQ,UVK,ECCC,rodrigoseguel@uchile.cl,KU,Dagmar%20Kubistin,EBAS"