[
https://issues.apache.org/jira/browse/HIVE-8448?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Chaoyu Tang updated HIVE-8448:
------------------------------
Description:
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 to fix this particular union issue but I noticed
that there are three versions of getCommonClass: getCommonClass,
getCommonClassForComparison, getCommonClassForUnionAll, and wonder if they need
refactoring.
was:
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
> 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
> Assignee: 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 to fix this particular union issue but I noticed
> that there are three versions of getCommonClass: getCommonClass,
> getCommonClassForComparison, getCommonClassForUnionAll, and wonder if they
> need refactoring.
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