[GitHub] incubator-quickstep pull request #271: QUICKSTEP-95: Fixed the exception due...

[asfgit]

Github user asfgit closed the pull request at:

https://github.com/apache/incubator-quickstep/pull/271


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[GitHub] incubator-quickstep pull request #271: QUICKSTEP-95: Fixed the exception due...

[zuyu]

GitHub user zuyu reopened a pull request:

https://github.com/apache/incubator-quickstep/pull/271

QUICKSTEP-95: Fixed the exception due to zero tuple estimation for th…

…e empty project expression.

The problem is that 
[tuple_slot_bytes_](https://github.com/apache/incubator-quickstep/blob/master/storage/SplitRowStoreTupleStorageSubBlock.cpp#L128)
 is ZERO if the project expression is empty, and 
[later](https://github.com/apache/incubator-quickstep/blob/master/storage/SplitRowStoreTupleStorageSubBlock.cpp#L142)
 results in a divide-by-zero exception.

It is easy to reproduce:

```
$ create table r (a int, b char(20));
$ insert into r values(1, 'madison');
$ create table s (a int, c float);
$ select s.a from r, s where r.a > 0;
```

```
I0619 18:26:45.097215 1944100864 PhysicalGenerator.cpp:196] Optimized 
physical plan:
TopLevelPlan
+-plan=NestedLoopsJoin
| +-left=Selection
| | +-input=TableReference[relation=r]
| | | +-AttributeReference[id=0,name=a,relation=r,type=Int]
| | | +-AttributeReference[id=1,name=b,relation=r,type=Char(20)]
| | +-filter_predicate=Greater
| | | +-AttributeReference[id=0,name=a,relation=r,type=Int]
| | | +-Literal[value=0,type=Int]
| | +-project_expressions=
| |   +-[]
| +-right=TableReference[relation=s]
| | +-AttributeReference[id=2,name=a,relation=s,type=Int]
| | +-AttributeReference[id=3,name=c,relation=s,type=Float]
| +-join_predicate=Literal[value=true]
| +-project_expressions=
|   +-AttributeReference[id=2,name=a,relation=s,type=Int]
+-output_attributes=
  +-AttributeReference[id=2,name=a,relation=s,type=Int]
```

Floating point exception: 8

You can merge this pull request into a Git repository by running:

$ git pull https://github.com/zuyu/incubator-quickstep quickstep-95

Alternatively you can review and apply these changes as the patch at:

https://github.com/apache/incubator-quickstep/pull/271.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

This closes #271


commit eb128ce3e6ae9e7dce5d7c4f05ca1f712640ac7d
Author: Zuyu Zhang 
Date:   2017-06-19T20:53:52Z

QUICKSTEP-95: Fixed the exception due to zero tuple estimation for the 
empty project expression.




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