Used below calculation to convert BigINT to Date for a Impala table.
Originally this Impala table was loaded from Oracle table by Sqoop. Sqoop converts Oracle date fields to BigInt fields.
Note: Parquet doesn’t support date type but it does support timestamp. Sqoop has some bug so it cannot do timestamp but there is two step workaround for this that’s how i end up in using Spark.
dateadd(‘second’, INT(([Start Date]/1000)+(8*60*60)-43200), #1970-01-01#)
QlikTab 