[Mondrian] Testing a Hive dialect

[Calum Miller]

I have time next week to help make necessary Mondrian dialect changes. Happy to start on Monday if Jira is updated?

Calum

Sent from my iPhone

On 11 Feb 2011, at 17:51, "Julian Hyde" <jhyde at pentaho.com> wrote:

> If it is difficult to fix HIVE-1922, we could possibly workaround issue by changing Dialect.generateOrderItem. (Every dialect tends to have different rules for how to generate an ORDER BY clause -- order by column name, order by ordinal, order by expression, order by ordinal only when applied to a set operation such as union, etc. -- so there's no harm having yet another behavior.)
>  
> Someone also mentioned that Hive only supports ANSI join syntax 'FROM t1 JOIN t2 ON t1.x = t2.y', whereas mondrian only generates 'FROM t1, t2 WHERE t1.x = t2.y'. Is this still an issue? We would need to fix either Hive or Mondrian's dialect. Mondrian's  dialect it probably easier.
>  
> Since other people have expressed an interest in a Hive dialect, it would be useful if you check in what you have right now, even though there are many failures. Send me the files and I will check them in.
>  
> Julian
>  
> 
> From: mondrian-bounces at pentaho.org [mailto:mondrian-bounces at pentaho.org] On Behalf Of Fu Hongwei
> Sent: Friday, February 11, 2011 3:53 AM
> To: 'Mondrian developer mailing list'
> Subject: Re: RE: [Mondrian] Testing a Hive dialect
> 
> Hi Julian,
> Thanks for the prompt reply.
> The test is running on Hive 0.7.0, but a patch will be needed. I've started a jira on Hive and will submit it soon too.
> https://issues.apache.org/jira/browse/HIVE-1922?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12987548#action_12987548
>  
> There are too many failures in the test suite.  I'm still working on it, but I will submit the DialectTest.java and HiveDialect.java, so people interested can work on it together.
> I think the point is first to make it running then speed it up.
> 2011-02-11
> Fu Hongwei
> 发件人： Julian Hyde
> 发送时间： 2011-02-11  00:19:26
> 收件人： 'Mondrian developer mailing list'
> 抄送：
> 主题： RE: [Mondrian] Testing a Hive dialect
> I am well aware of the compromises with Hive. There is certainly an impedance mismatch between hadoop and the real-time analysis, and that is reflected in query response time. It is still useful  to have a Hive dialect, because as you say, Hive is improving all the time. And Pentaho is thinking about ways to bridge the impedance mismatch.
>  
> Can please you attach your code to the jira case as a patch? I will submit it.
>  
> Also please attach the output of the test suite, and describe the version of Hive you are running    against. That will be a reference point for others who are working on Hive.
>  
> Julian
> 
> From: mondrian-bounces at pentaho.org [mailto:mondrian-bounces at pentaho.org] On Behalf Of Fu Hongwei
> Sent: Thursday, February 10, 2011 1:29 AM
> To: mondrian
> Subject: [Mondrian] Testing a Hive dialect 
> 
> Hi,
> I'm new to the community. I don't know who to ask this for.
> I've written a Hive dialect for mondrian and been testing it.
> The DialectTest is passed, but it's still failing other tests.
>  
> From what I can see it's still a long way to make an integration
> of Hive and Mondrian practical.
> 1. It's really slow. It takes 1 or 2 days to run through all the tests,
> a low end estimation. The latency is too big for most applications.
> It might take some major architectural change on the Hive side to solve
> this problem.
> 2. Hive ql is still at a rather immature stage, partly because it's not
> really intended to be a full featured relational database. There are some
>  bugs too, like the join behavior is incorrect at the current trunk.
>  
> I know there is already a jira about it.
> http://jira.pentaho.com/browse/MONDRIAN-789 
> How can I submit the code? Thanks
> 2011-02-10
> Fu Hongwei
> _______________________________________________
> Mondrian mailing list
> Mondrian at pentaho.org
> http://lists.pentaho.org/mailman/listinfo/mondrian
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