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From Bejoy Ks <bejoy...@yahoo.com>
Subject Re: Database/Schema , INTERVAL and SQL IN usages in Hive
Date Thu, 24 Feb 2011 14:23:18 GMT
Yes Ajo time was the concern. I just got a chance though the in memory join 
implementation within hive and it is great.
Sorry for the confusion :)




________________________________
From: Ajo Fod <ajo.fod@gmail.com>
To: user@hive.apache.org
Sent: Wed, February 23, 2011 8:01:07 PM
Subject: Re: Database/Schema , INTERVAL and SQL IN usages in Hive

Better in what sense? ... if it is time you are concerned about there are in 
memory joins.

-Ajo


On Wed, Feb 23, 2011 at 3:39 AM, Bejoy Ks <bejoy_ks@yahoo.com> wrote:

Ajo,
>    If we have a good number of elements in the comparison set then going for a 
>table would be beneficial. But in case of a few elements say 5 wont multiple '=' 
>be better?
>
>Regards 
>Bejoy KS
>
>
>
>
________________________________
From: Ajo Fod <ajo.fod@gmail.com>
>
>To: user@hive.apache.org
>Sent: Mon, February 21, 2011 10:04:41 PM
>
>Subject: Re: Database/Schema , INTERVAL and SQL IN usages in  Hive
>
>
>On using SQL IN ... what would happen if you created a short table with the 
>enteries in the IN clause and used a "inner join" ?
>
>-Ajo
>
>
>On Mon, Feb 21, 2011 at 7:57 AM, Bejoy Ks <bejoy_ks@yahoo.com> wrote:
>
>Thanks Jov for the quick response
>>
>>Could you please let me know which is the latest stable version of hive. Also 
>>how would you find out your hive version from command line?
>>
>>Regarding the SQL IN  I'm also currently using multiple '=' in my jobs, but 
>>still wanted to know whether there would be some better usage for the same apart 
>>from this. 
>>
>>
>>
>>Regards
>>Bejoy KS
>>
>>
>>
>>
>>
>>
>>
________________________________
 From: Jov <zhao6014@gmail.com>
>>To: user@hive.apache.org
>>Sent: Mon, February 21, 2011 9:09:34 PM
>>Subject: Re: Database/Schema , INTERVAL and SQL IN usages in Hive
>>
>>
>>
>>
>>在 2011-2-21 下午10:54,"Bejoy Ks" <bejoy_ks@yahoo.com>写道:
>>>
>>> Hi Experts
>>>      I'm using hive for a few projects and i found it a great tool in hadoop
to 
>>>process end to end structured data. Unfortunately I'm facing a few challenges

>>>out here as follows
>>>
>>> Availability of database/schemas in Hive
>>> I'm having multiple projects running in hive each having fairly large number
of 
>>>tables. With this much tables all together it is  looking a bit  messed up. Is

>>>there any option of creating database/schema in Hive so that I can maintain the

>>>tables in different databases/schemas corresponding to each project.
>>it seems the resent version has already support database ddl,so,you can use 
>>create database. 
>>
>>> Using INTERVAL 
>>>     I need to replicate a job running in Teradata edw into hive, i'm facing a

>>>challenge out here.Not able to identify a similar usage corresponding to 
>>>Interval in teradata within hive. Here is the snippet where I'm facing the issue
>>>  *** where 1.seq_id = r4.seq_id and r4.mc_datetime >= (r1.rc_datetime + 
>>>INTERVAL '05' HOUR)
>>> In this query how do i replicate the last part in hive ie (r1.rc_datetime + 
>>>INTERVAL '05' HOUR) , where it is adding 5 hours to the obtained time stamp 
>>>rc_datetime.
>>> *The where condition is part of a very large query involving multiple table 
>>>joins.
>>hive do not have date or timestamp data type,all such type is string,but you can 
>>write your udf to implement similar function 
>>
>>>
>>> Using IN 
>>>     How do we replicate the SQL IN function in hive
>>> ie *** where R1.seq_id = r4.seq_id and r1.PROCCESS_PHASE IN ( 'Production', 
>>>'Stage' , 'QA', 'Development')
>>> the last part of the query is where i'm facing the challenge r1.PROCCESS_PHASE

>>>IN ( 'Production', 'Stage' , 'QA', 'Development')
>>> *The where condition is part of a very large query involving multiple table 
>>>joins.
>>you can use or,e.g.
>>'x in(1,2)' can be 'x=1 or x=2'
>>> Please advise.
>>>
>>> Regards
>>> Bejoy KS
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>
>



      
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