I have two delta tables I'm reading, joining and writing. They both have timestamps, so I'm using those as watermarks and I can join the data without problems. However, when I try to group it, the stream doesn't write anything to the delta anymore.
actionResult = actionResult.withColumnRenamed("timestamp", "secTimestamp") \
.withWatermark("secTimestamp", "1 day")
combi = action.join(actionResult,
(action.actionID == actionResult.actionID) &
expr("secTimestamp < timestamp + interval 1 day"),
how="left") \
.drop("secTimestamp").drop(actionResult.actionID) # still able to write
combi = combi.withWatermark("timestamp", "1 day") \
.groupby("ShipmentID", F.window("timestamp", "1 day", "1 day")) \
.agg(sparkMax(col('timestamp')).alias("timestamp"),
collect_list('HubID').alias('HubID')) # no results
Any insights on what might be wrong?