Interpreting explain plan in hive

[pandees waran <pa...@gmail.com>]

Hi,

What are the key areas we need to check in the explain plan generated in Hive?
I have checked the documentation, it's not detailed about the above question.
https://cwiki.apache.org/confluence/display/Hive/LanguageManual+Explain
I have similar kind of question asked in our forum, which is unanswered.
http://mail-archives.apache.org/mod_mbox/hive-user/201107.mbox/%3CCAAG3+BGHadR65FnR5udmGP9=QcriHuubnR8WR-VbxczdOhA=EQ@mail.gmail.com%3E

In summary, how we can distinguish a good/bad plan ?

Thanks for your help.
-- 
Thanks,
Pandeeswaran

Re: Interpreting explain plan in hive

[Edward Capriolo <ed...@gmail.com>]

The only bad plan would be a plan that ends up producing the wrong result,
or throwing an exception. generally I look to see if there is a way to have
less map/reduce stages, the best plan is usually the one that does the job
in a single map reduce, or even better a single map only job.


On Fri, Aug 23, 2013 at 1:28 AM, pandees waran <pa...@gmail.com> wrote:

> Hi,
>
> What are the key areas we need to check in the explain plan generated in
> Hive?
> I have checked the documentation, it's not detailed about the above
> question.
> https://cwiki.apache.org/confluence/display/Hive/LanguageManual+Explain
> I have similar kind of question asked in our forum, which is unanswered.
>
> http://mail-archives.apache.org/mod_mbox/hive-user/201107.mbox/%3CCAAG3+BGHadR65FnR5udmGP9=QcriHuubnR8WR-VbxczdOhA=EQ@mail.gmail.com%3E
>
> In summary, how we can distinguish a good/bad plan ?
>
> Thanks for your help.
> --
> Thanks,
> Pandeeswaran
>