qualifier
Parameters
value
Qualifier of the column. Columns in the parent column family that has this exact qualifier are exposed as . field. If the qualifier is valid UTF-8 string, it can be specified in the qualifierString field. Otherwise, a base-64 encoded value must be set to qualifierEncoded. The column field name is the same as the column qualifier. However, if the qualifier is not a valid BigQuery field identifier i.e. does not match a-zA-Z0-9_*, a valid identifier must be provided as fieldName.