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From Appan Thirumaligai <appanhiv...@gmail.com>
Subject Re: Partition Columns
Date Thu, 14 May 2015 23:31:51 GMT
I agree with you Viral. I see the same behavior as well. We are on Hive
0.13 for the cluster where I'm testing this.

On Thu, May 14, 2015 at 2:16 PM, Viral Bajaria <viral.bajaria@gmail.com>
wrote:

> Hi Appan,
>
> In my experience I have seen that Query 2 does not use partition pruning
> because it's not a straight up filtering and involves using functions (aka
> UDFs).
>
> What version of Hive are you using ?
>
> Thanks,
> Viral
>
>
>
> On Thu, May 14, 2015 at 1:48 PM, Appan Thirumaligai <appanhiveug@gmail.com
> > wrote:
>
>> Hi,
>>
>> I have a question on Hive Optimizer. I have a table with partition
>> columns  eg.,Sales partitioned by year, month, day. Assume that I have two
>> years worth of data on this table. I'm running two queries on this table.
>>
>> Query 1: Select * from Sales where year=2015 and month = 5 and day
>> between 1 and 7
>>
>> Query 2: Select * from Sales where concat_ws('-',cast(year as
>> string),lpad(cast(month as string),2,'0'),lpad(cast(day as string),2,'0'))
>> between '2015-01-01' and '2015-01-07'
>>
>> When I ran Explain command on the above two queries I get a Filter
>> operation for the 2nd Query and there is no Filter Operation for the first
>> query.
>>
>> My question is: Do both queries use the partitions or is it used only in
>> Query 1 and for Query 2 it will be a scan of all the data?
>>
>> Thanks for your help.
>>
>> Thanks,
>> Appan
>>
>
>

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