Re: Review Request 65479: HIVE-18523 Fix summary row in case there are no inputs

2018-02-06 Thread Zoltan Haindrich 

---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/65479/
---

(Updated Feb. 6, 2018, 5:15 p.m.)


Review request for hive, Ashutosh Chauhan and Prasanth_J.


Changes
---

update


Bugs: HIVE-18523
https://issues.apache.org/jira/browse/HIVE-18523


Repository: hive-git


Description
---

* ensure that mapper operators are started up - but only if empty grouping is 
present


Diffs (updated)
-

  ql/src/java/org/apache/hadoop/hive/ql/exec/GroupByOperator.java 6a0f0de2a5 
  ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java 
PRE-CREATION 
  ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java 941dd58f27 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java 976b537033 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapRunner.java PRE-CREATION 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapper.java 150382a8d5 
  ql/src/java/org/apache/hadoop/hive/ql/exec/tez/HiveSplitGenerator.java 
98f4bc01c8 
  ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java 
45d809a182 
  ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java 
e4dfc009d9 
  ql/src/java/org/apache/hadoop/hive/ql/io/HiveInputFormat.java c3b846c4d2 
  ql/src/java/org/apache/hadoop/hive/ql/io/NullRowsInputFormat.java 6a372a3f47 
  ql/src/java/org/apache/hadoop/hive/ql/plan/MapWork.java f2b2fc57a0 
  ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java ecfb118b41 
  ql/src/test/queries/clientpositive/groupby_rollup_empty.q 432d8c448a 
  ql/src/test/results/clientpositive/groupby_rollup_empty.q.out 7359140e29 
  ql/src/test/results/clientpositive/llap/groupby_rollup_empty.q.out d2b57455a3 


Diff: https://reviews.apache.org/r/65479/diff/3/

Changes: https://reviews.apache.org/r/65479/diff/2-3/


Testing
---

added new testcase for union


Thanks,

Zoltan Haindrich

Re: Review Request 65479: HIVE-18523 Fix summary row in case there are no inputs

2018-02-06 Thread Zoltan Haindrich 


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java
> > Lines 213 (patched)
> > 
> >
> > Do we need this? Reducers are always launched when when there is no 
> > mapper. So, this seems unnecessary.
> 
> Zoltan Haindrich wrote:
> I can remove it...but I think IConfigureJobConf can be used as a general 
> way to make modifications like this - in the current case this setting has 
> effectively no effect on the reducers...they are being run anyway
> 
> I think that after this patch the code from PlanUtils.configureJobConf 
> could be moved to FileSinkOperator by using the new interface
> I feel that core constructs like ReduceWork should depend less on 
> explicit operator implementations and more on interfaces if possible.
> 
> Ashutosh Chauhan wrote:
> I agree that a general mechanism has some value. However, my concern is 
> extra CPU we will be wasting doing nothing. In a large plan with 100s of 
> vertices going through all RSs will be non-zero cost we will be paying. So, 
> unless we need it we should avoid it.

I see your point, I've removed it.


- Zoltan


---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/65479/#review196840
---


On Feb. 6, 2018, 10:24 a.m., Zoltan Haindrich wrote:
> 
> ---
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/65479/
> ---
> 
> (Updated Feb. 6, 2018, 10:24 a.m.)
> 
> 
> Review request for hive, Ashutosh Chauhan and Prasanth_J.
> 
> 
> Bugs: HIVE-18523
> https://issues.apache.org/jira/browse/HIVE-18523
> 
> 
> Repository: hive-git
> 
> 
> Description
> ---
> 
> * ensure that mapper operators are started up - but only if empty grouping is 
> present
> 
> 
> Diffs
> -
> 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/GroupByOperator.java 6a0f0de2a5 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java 
> PRE-CREATION 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java 941dd58f27 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java 976b537033 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapRunner.java 
> PRE-CREATION 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapper.java 150382a8d5 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/tez/HiveSplitGenerator.java 
> 98f4bc01c8 
>   
> ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java 
> 45d809a182 
>   ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java 
> e4dfc009d9 
>   ql/src/java/org/apache/hadoop/hive/ql/io/HiveInputFormat.java c3b846c4d2 
>   ql/src/java/org/apache/hadoop/hive/ql/io/NullRowsInputFormat.java 
> 6a372a3f47 
>   ql/src/java/org/apache/hadoop/hive/ql/plan/MapWork.java f2b2fc57a0 
>   ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java ecfb118b41 
>   ql/src/test/queries/clientpositive/groupby_rollup_empty.q 432d8c448a 
>   ql/src/test/results/clientpositive/groupby_rollup_empty.q.out 7359140e29 
>   ql/src/test/results/clientpositive/llap/groupby_rollup_empty.q.out 
> d2b57455a3 
> 
> 
> Diff: https://reviews.apache.org/r/65479/diff/2/
> 
> 
> Testing
> ---
> 
> added new testcase for union
> 
> 
> Thanks,
> 
> Zoltan Haindrich
> 
>

Re: Review Request 65479: HIVE-18523 Fix summary row in case there are no inputs

2018-02-06 Thread Ashutosh Chauhan 


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java
> > Lines 213 (patched)
> > 
> >
> > Do we need this? Reducers are always launched when when there is no 
> > mapper. So, this seems unnecessary.
> 
> Zoltan Haindrich wrote:
> I can remove it...but I think IConfigureJobConf can be used as a general 
> way to make modifications like this - in the current case this setting has 
> effectively no effect on the reducers...they are being run anyway
> 
> I think that after this patch the code from PlanUtils.configureJobConf 
> could be moved to FileSinkOperator by using the new interface
> I feel that core constructs like ReduceWork should depend less on 
> explicit operator implementations and more on interfaces if possible.

I agree that a general mechanism has some value. However, my concern is extra 
CPU we will be wasting doing nothing. In a large plan with 100s of vertices 
going through all RSs will be non-zero cost we will be paying. So, unless we 
need it we should avoid it.


- Ashutosh


---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/65479/#review196840
---


On Feb. 6, 2018, 10:24 a.m., Zoltan Haindrich wrote:
> 
> ---
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/65479/
> ---
> 
> (Updated Feb. 6, 2018, 10:24 a.m.)
> 
> 
> Review request for hive, Ashutosh Chauhan and Prasanth_J.
> 
> 
> Bugs: HIVE-18523
> https://issues.apache.org/jira/browse/HIVE-18523
> 
> 
> Repository: hive-git
> 
> 
> Description
> ---
> 
> * ensure that mapper operators are started up - but only if empty grouping is 
> present
> 
> 
> Diffs
> -
> 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/GroupByOperator.java 6a0f0de2a5 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java 
> PRE-CREATION 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java 941dd58f27 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java 976b537033 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapRunner.java 
> PRE-CREATION 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapper.java 150382a8d5 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/tez/HiveSplitGenerator.java 
> 98f4bc01c8 
>   
> ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java 
> 45d809a182 
>   ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java 
> e4dfc009d9 
>   ql/src/java/org/apache/hadoop/hive/ql/io/HiveInputFormat.java c3b846c4d2 
>   ql/src/java/org/apache/hadoop/hive/ql/io/NullRowsInputFormat.java 
> 6a372a3f47 
>   ql/src/java/org/apache/hadoop/hive/ql/plan/MapWork.java f2b2fc57a0 
>   ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java ecfb118b41 
>   ql/src/test/queries/clientpositive/groupby_rollup_empty.q 432d8c448a 
>   ql/src/test/results/clientpositive/groupby_rollup_empty.q.out 7359140e29 
>   ql/src/test/results/clientpositive/llap/groupby_rollup_empty.q.out 
> d2b57455a3 
> 
> 
> Diff: https://reviews.apache.org/r/65479/diff/2/
> 
> 
> Testing
> ---
> 
> added new testcase for union
> 
> 
> Thanks,
> 
> Zoltan Haindrich
> 
>

Re: Review Request 65479: HIVE-18523 Fix summary row in case there are no inputs

2018-02-06 Thread Zoltan Haindrich 

---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/65479/
---

(Updated Feb. 6, 2018, 10:24 a.m.)


Review request for hive, Ashutosh Chauhan and Prasanth_J.


Changes
---

address review comments


Bugs: HIVE-18523
https://issues.apache.org/jira/browse/HIVE-18523


Repository: hive-git


Description
---

* ensure that mapper operators are started up - but only if empty grouping is 
present


Diffs (updated)
-

  ql/src/java/org/apache/hadoop/hive/ql/exec/GroupByOperator.java 6a0f0de2a5 
  ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java 
PRE-CREATION 
  ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java 941dd58f27 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java 976b537033 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapRunner.java PRE-CREATION 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapper.java 150382a8d5 
  ql/src/java/org/apache/hadoop/hive/ql/exec/tez/HiveSplitGenerator.java 
98f4bc01c8 
  ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java 
45d809a182 
  ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java 
e4dfc009d9 
  ql/src/java/org/apache/hadoop/hive/ql/io/HiveInputFormat.java c3b846c4d2 
  ql/src/java/org/apache/hadoop/hive/ql/io/NullRowsInputFormat.java 6a372a3f47 
  ql/src/java/org/apache/hadoop/hive/ql/plan/MapWork.java f2b2fc57a0 
  ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java ecfb118b41 
  ql/src/test/queries/clientpositive/groupby_rollup_empty.q 432d8c448a 
  ql/src/test/results/clientpositive/groupby_rollup_empty.q.out 7359140e29 
  ql/src/test/results/clientpositive/llap/groupby_rollup_empty.q.out d2b57455a3 


Diff: https://reviews.apache.org/r/65479/diff/2/

Changes: https://reviews.apache.org/r/65479/diff/1-2/


Testing
---

added new testcase for union


Thanks,

Zoltan Haindrich

Re: Review Request 65479: HIVE-18523 Fix summary row in case there are no inputs

2018-02-06 Thread Zoltan Haindrich 


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java
> > Lines 24 (patched)
> > 
> >
> > Add: Intended only for compilation phase.

added


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java
> > Lines 259 (patched)
> > 
> >
> > Is this needed?

unfortunately yes; the following makes it needed:

* we are currently using mapreduce "old" api
* 
[MapRunner#map](https://github.com/apache/hadoop/blob/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/MapRunner.java#L54)
 only passes the OutputCollector if there are *at least* one inputs 
* 
[ExecMapper](https://github.com/apache/hive/blob/f33db1f68c68b552b9888988f818c03879749461/ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapper.java#L144)
 at the minute the first record is start getting in; it sets the OC correctly
* note: It's interesting that the ReduceSink needs the OutputCollector to pass 
the output...but it can "silently" ignore record if the OC is unset 
[here](https://github.com/apache/hive/blob/f33db1f68c68b552b9888988f818c03879749461/ql/src/java/org/apache/hadoop/hive/ql/exec/ReduceSinkOperator.java#L500)
 - not sure if this have already hidden bugs or not...
* ExecMapRunner only adds the ability to set the OC in case there are 0 rows - 
and it enables closeOp() -s to emit records if they have to


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapRunner.java
> > Lines 29 (patched)
> > 
> >
> > Why do we need this class?

see previous comment


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/exec/tez/HiveSplitGenerator.java
> > Line 247 (original), 246-248 (patched)
> > 
> >
> > This may result in extra memory allocation. If this change is not 
> > necessary, can we leave it as is?

this was some leftover from an earlier version of the patch...removed


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java
> > Lines 453 (patched)
> > 
> >
> > Please add comment.

added:

   in case the empty grouping set is preset; but no output has done
   the "summary row" still needs to be emitted


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java
> > Lines 580 (patched)
> > 
> >
> > Add comment on need for this.

I've added:

If there are no inputs; the Execution engine skips the operator tree.
To prevent it from happening; an opaque  ZeroRows input is added here - when 
needed.


> On Feb. 5, 2018, 11:05 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java
> > Lines 213 (patched)
> > 
> >
> > Do we need this? Reducers are always launched when when there is no 
> > mapper. So, this seems unnecessary.

I can remove it...but I think IConfigureJobConf can be used as a general way to 
make modifications like this - in the current case this setting has effectively 
no effect on the reducers...they are being run anyway

I think that after this patch the code from PlanUtils.configureJobConf could be 
moved to FileSinkOperator by using the new interface
I feel that core constructs like ReduceWork should depend less on explicit 
operator implementations and more on interfaces if possible.


- Zoltan


---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/65479/#review196840
---


On Feb. 2, 2018, 12:23 p.m., Zoltan Haindrich wrote:
> 
> ---
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/65479/
> ---
> 
> (Updated Feb. 2, 2018, 12:23 p.m.)
> 
> 
> Review request for hive, Ashutosh Chauhan and Prasanth_J.
> 
> 
> Bugs: HIVE-18523
> https://issues.apache.org/jira/browse/HIVE-18523
> 
> 
> Repository: hive-git
> 
> 
> Description
> ---
> 
> * ensure that mapper operators are started up - but only if empty grouping is 
> present
> 
> 
> Diffs
> -
> 
>

Re: Review Request 65479: HIVE-18523 Fix summary row in case there are no inputs

2018-02-05 Thread Ashutosh Chauhan 

---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/65479/#review196840
---




ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java
Lines 24 (patched)


Add: Intended only for compilation phase.



ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java
Lines 24 (patched)


Add: Only during compilation.



ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java
Lines 259 (patched)


Is this needed?



ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapRunner.java
Lines 29 (patched)


Why do we need this class?



ql/src/java/org/apache/hadoop/hive/ql/exec/tez/HiveSplitGenerator.java
Line 247 (original), 246-248 (patched)


This may result in extra memory allocation. If this change is not 
necessary, can we leave it as is?



ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java
Lines 453 (patched)


Please add comment.



ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java
Lines 580 (patched)


Add comment on need for this.



ql/src/java/org/apache/hadoop/hive/ql/io/HiveInputFormat.java
Lines 505 (patched)


Add comment on need for this.



ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java
Lines 213 (patched)


Do we need this? Reducers are always launched when when there is no mapper. 
So, this seems unnecessary.


- Ashutosh Chauhan


On Feb. 2, 2018, 12:23 p.m., Zoltan Haindrich wrote:
> 
> ---
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/65479/
> ---
> 
> (Updated Feb. 2, 2018, 12:23 p.m.)
> 
> 
> Review request for hive, Ashutosh Chauhan and Prasanth_J.
> 
> 
> Bugs: HIVE-18523
> https://issues.apache.org/jira/browse/HIVE-18523
> 
> 
> Repository: hive-git
> 
> 
> Description
> ---
> 
> * ensure that mapper operators are started up - but only if empty grouping is 
> present
> 
> 
> Diffs
> -
> 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/GroupByOperator.java 
> 6a0f0de2a5e84770c6446af41710d972d813c7bc 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java 
> PRE-CREATION 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java 
> d7b3e4b2fd3ee1a8e2795095a6c55442de2b38e0 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java 
> 976b537033abda5d5ab8b77a7e7d6fb9c84e5a19 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapRunner.java 
> PRE-CREATION 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapper.java 
> 150382a8d58fd4ba44e4d9b78a80173ab984e776 
>   ql/src/java/org/apache/hadoop/hive/ql/exec/tez/HiveSplitGenerator.java 
> 98f4bc01c8526422348a38f8d8632e0899d695ee 
>   
> ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java 
> 45d809a1820fcb6ea5e1e5c15aee7de91a4c36c8 
>   ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java 
> e4dfc009d95f4302bd1fcdff2276e11bed68d2e0 
>   ql/src/java/org/apache/hadoop/hive/ql/io/HiveInputFormat.java 
> c3b846c4d2fee8691b4952b9f6cf4dd1d8bd632f 
>   ql/src/java/org/apache/hadoop/hive/ql/io/NullRowsInputFormat.java 
> 6a372a3f47e3ac2ae2b2e583541b3a19e5d525f3 
>   ql/src/java/org/apache/hadoop/hive/ql/plan/MapWork.java 
> f2b2fc57a03b368707968eb503139e51218008ca 
>   ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java 
> ecfb118b41bfa5b7d593b7e801a37f0a7b5b0b5e 
>   ql/src/test/queries/clientpositive/groupby_rollup_empty.q 
> 432d8c448a05f51db9ecf9940bce599dfd598a70 
>   ql/src/test/results/clientpositive/groupby_rollup_empty.q.out 
> 7359140e29fc63eebbab42ab385187be6bfc66e1 
>   ql/src/test/results/clientpositive/llap/groupby_rollup_empty.q.out 
> d2b57455a3640387d8bc5f2d415a7af25eb55341 
> 
> 
> Diff: https://reviews.apache.org/r/65479/diff/1/
> 
> 
> Testing
> ---
> 
> added new testcase for union
> 
> 
> Thanks,
> 
> Zoltan Haindrich
> 
>

Review Request 65479: HIVE-18523 Fix summary row in case there are no inputs

2018-02-02 Thread Zoltan Haindrich 

---
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/65479/
---

Review request for hive, Ashutosh Chauhan and Prasanth_J.


Bugs: HIVE-18523
https://issues.apache.org/jira/browse/HIVE-18523


Repository: hive-git


Description
---

* ensure that mapper operators are started up - but only if empty grouping is 
present


Diffs
-

  ql/src/java/org/apache/hadoop/hive/ql/exec/GroupByOperator.java 
6a0f0de2a5e84770c6446af41710d972d813c7bc 
  ql/src/java/org/apache/hadoop/hive/ql/exec/IConfigureJobConf.java 
PRE-CREATION 
  ql/src/java/org/apache/hadoop/hive/ql/exec/Utilities.java 
d7b3e4b2fd3ee1a8e2795095a6c55442de2b38e0 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java 
976b537033abda5d5ab8b77a7e7d6fb9c84e5a19 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapRunner.java PRE-CREATION 
  ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecMapper.java 
150382a8d58fd4ba44e4d9b78a80173ab984e776 
  ql/src/java/org/apache/hadoop/hive/ql/exec/tez/HiveSplitGenerator.java 
98f4bc01c8526422348a38f8d8632e0899d695ee 
  ql/src/java/org/apache/hadoop/hive/ql/exec/vector/VectorGroupByOperator.java 
45d809a1820fcb6ea5e1e5c15aee7de91a4c36c8 
  ql/src/java/org/apache/hadoop/hive/ql/io/CombineHiveInputFormat.java 
e4dfc009d95f4302bd1fcdff2276e11bed68d2e0 
  ql/src/java/org/apache/hadoop/hive/ql/io/HiveInputFormat.java 
c3b846c4d2fee8691b4952b9f6cf4dd1d8bd632f 
  ql/src/java/org/apache/hadoop/hive/ql/io/NullRowsInputFormat.java 
6a372a3f47e3ac2ae2b2e583541b3a19e5d525f3 
  ql/src/java/org/apache/hadoop/hive/ql/plan/MapWork.java 
f2b2fc57a03b368707968eb503139e51218008ca 
  ql/src/java/org/apache/hadoop/hive/ql/plan/ReduceWork.java 
ecfb118b41bfa5b7d593b7e801a37f0a7b5b0b5e 
  ql/src/test/queries/clientpositive/groupby_rollup_empty.q 
432d8c448a05f51db9ecf9940bce599dfd598a70 
  ql/src/test/results/clientpositive/groupby_rollup_empty.q.out 
7359140e29fc63eebbab42ab385187be6bfc66e1 
  ql/src/test/results/clientpositive/llap/groupby_rollup_empty.q.out 
d2b57455a3640387d8bc5f2d415a7af25eb55341 


Diff: https://reviews.apache.org/r/65479/diff/1/


Testing
---

added new testcase for union


Thanks,

Zoltan Haindrich