> On Dec. 2, 2016, 9:10 p.m., Ashutosh Chauhan wrote:
> > ql/src/java/org/apache/hadoop/hive/ql/optimizer/StatsOptimizer.java, line
> > 182
> > <https://reviews.apache.org/r/54284/diff/1/?file=1574510#file1574510line182>
> >
> > Is there any differnce between NULL & constant? It seems you are not
> > making use of NULL any where.
Yes, I have make use of NULL. Please See
{code}
if (getGbyKeyType(pgbyOp) == GbyKeyType.OTHER) {
return null;
}
// we already check if rowCnt is null and rowCnt==0 means table is
// empty.
else if (getGbyKeyType(pgbyOp) == GbyKeyType.CONSTANT && rowCnt == 0) {
return null;
}
{code}
That means, only if it is groupby constant and rowCnt=0, we skip the
StatsOptimizer.
If it is NULL, which should be the 3rd condition (if, else if, else), we
continue.
- pengcheng
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https://reviews.apache.org/r/54284/#review157823
-----------------------------------------------------------
On Dec. 2, 2016, 1:23 a.m., pengcheng xiong wrote:
>
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/54284/
> -----------------------------------------------------------
>
> (Updated Dec. 2, 2016, 1:23 a.m.)
>
>
> Review request for hive and Ashutosh Chauhan.
>
>
> Repository: hive-git
>
>
> Description
> -------
>
> HIVE-13452
>
>
> Diffs
> -----
>
> ql/src/java/org/apache/hadoop/hive/ql/optimizer/StatsOptimizer.java 17510e9
> ql/src/test/queries/clientpositive/constGby.q PRE-CREATION
> ql/src/test/results/clientpositive/constGby.q.out PRE-CREATION
>
> Diff: https://reviews.apache.org/r/54284/diff/
>
>
> Testing
> -------
>
>
> Thanks,
>
> pengcheng xiong
>
>
