Thanks for reply, but using this method I got an exception:
"Exception in thread "main"
org.apache.spark.sql.streaming.StreamingQueryException: nondeterministic
expressions are only allowed in
Project, Filter, Aggregate or Window"
Can you give more advice?
Michael Armbrust <mich...@databricks.com>于2017年9月12日周二 上午4:48写道：
> import org.apache.spark.sql.functions._
>
> df.withColumn("window", window(current_timestamp(), "15 minutes"))
>
> On Mon, Sep 11, 2017 at 3:03 AM, 张万新 <kevinzwx1...@gmail.com> wrote:
>
>> Hi,
>>
>> In structured streaming how can I add a column to a dataset with current
>> system time aligned with 15 minutes?
>>
>> Thanks.
>>
>
>
