Stateful function should be called for all input rows but in if/when clause, it cannot be guaranteed.
Any reason to declare "protect_column" function to be stateful? Thanks, Navis 2014-09-25 3:42 GMT+09:00 Dan Fan <d...@appnexus.com>: > Hi Hive Users: > > I have a hive generic hive udf which is called protect_column. > The udf works fine when I call it along. > But when I run the following query: > > > select case when id = 5 then protect_column(id, 'age', 12L) else id end > from one_row_table ; > > > It says > > > Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Stateful > expressions cannot be used inside of CASE > > > I was reading the source code. And I think it is related to GenericCase > and GenericWhen according to > > > https://svn.apache.org/repos/asf/hive/trunk/ql/src/java/org/apache/hadoop/hive/ql/exec/ExprNodeGenericFuncEvaluator.java?p=1197837 > > Could anyone help explain explicitly what exactly is genericCase > GenericWhen and why we cannot put the udf inside a case when ? > > Thanks for your time helping me out > > Best > > Dan >
