Returns the oldest value, determined by the timecode, for each group. FIRST is a single-threaded function.
To invoke the FIRST function, use the GROUP BY TIME clause.
The return value is the same data type as the input data type.
Nulls are not included in the result computation.
FIRST is only valid on numeric data.
In the event of a tie, such as simultaneous timecode values for a particular group, all tied results are returned. If a sequence number is present with the data, it can break a tie, assuming it is unique across identical timecode values.