The name of the timeseries column. For Kafka sources, use dot-prefixed path notation to
reference fields within the key or value schema (e.g., "value.event_timestamp"). For nested
fields, the leaf node name (e.g., "event_timestamp" from "value.event_details.event_timestamp")
is what will be present in materialized tables and expected to match at query time.
Colon-prefixed notation (e.g., "value:event_timestamp") is supported for
backwards compatibility but is deprecated; migrate to dot notation.
The name of the timeseries column. For Kafka sources, use dot-prefixed path notation to reference fields within the key or value schema (e.g., "value.event_timestamp"). For nested fields, the leaf node name (e.g., "event_timestamp" from "value.event_details.event_timestamp") is what will be present in materialized tables and expected to match at query time. Colon-prefixed notation (e.g., "value:event_timestamp") is supported for backwards compatibility but is deprecated; migrate to dot notation.