Chaoyu Tang created HIVE-8448:
---------------------------------
Summary: Union All might not work due to the type conversion issue
Key: HIVE-8448
URL: https://issues.apache.org/jira/browse/HIVE-8448
Project: Hive
Issue Type: Bug
Reporter: Chaoyu Tang
Priority: Minor
create table t1 (val date);
insert overwrite table t1 select '2014-10-10' from src limit 1;
create table t2 (val varchar(10));
insert overwrite table t2 select '2014-10-10' from src limit 1;
==
Query:
select t.val from
(select val from t1
union all
select val from t1
union all
select val from t2
union all
select val from t1) t;
==
Will throw exception:
{code}
Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Incompatible types
for union operator
at
org.apache.hadoop.hive.ql.exec.UnionOperator.initializeOp(UnionOperator.java:86)
at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:380)
at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:464)
at
org.apache.hadoop.hive.ql.exec.Operator.initializeChildren(Operator.java:420)
at
org.apache.hadoop.hive.ql.exec.SelectOperator.initializeOp(SelectOperator.java:65)
at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:380)
at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:464)
at
org.apache.hadoop.hive.ql.exec.Operator.initializeChildren(Operator.java:420)
at
org.apache.hadoop.hive.ql.exec.TableScanOperator.initializeOp(TableScanOperator.java:193)
at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:380)
at
org.apache.hadoop.hive.ql.exec.MapOperator.initializeOp(MapOperator.java:443)
at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:380)
at
org.apache.hadoop.hive.ql.exec.mr.ExecMapper.configure(ExecMapper.java:133)
... 22 more
{code}
It was because at this query parse step, getCommonClassForUnionAll is used, but
at execution getCommonClass is used. They are not used consistently in union.
The later one does not support the implicit conversion from date to string,
which is the problem cause.
The change might be simple
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
