Hi Jiahui, Yes, if they arrive at the same millisecond, they are perserved in the arriving order.
Best, Jark On Mon, 11 May 2020 at 23:17, Jiahui Jiang <qzhzm173...@hotmail.com> wrote: > Hello! I'm writing a SQL query with a OVER window function ordered by > processing time. > > I'm wondering since timestamp is only millisecond granularity. > > For a query using over window and sorted on processing time column, for > example, > ``` > SELECT col1, > max(col2) OVER (PARTITION BY col1, ORDER BY _processing_time_column) > FROM table > ``` > > If 2 records have the same processing timestamp (they arrived the operator > at the exact same millisecond), is the order guaranteed to be preserved > after the window function? If not, what would to the recommended workaround > to keep the order? > > Thank you! > Jiahui >