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Hive >> mail # user >> ALTER TABLE CHANGE COLUMN issue


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Re: ALTER TABLE CHANGE COLUMN issue
Right, the very important thing to remember about ALTER TABLE is that it
only changes metadata about your table. It doesn't modify the data in any
way. You have to do that yourself.

On Wed, Jan 30, 2013 at 2:17 AM, Nitin Pawar <[EMAIL PROTECTED]>wrote:

> after u did alter table, did you add any new data to table with new
> schema?
>
> for the old data already present in data, if you add anything new in
> columns it will be null value
>
>
> On Wed, Jan 30, 2013 at 1:44 PM, hardik doshi <[EMAIL PROTECTED]>wrote:
>
>> Hi,
>>
>> I am running into an issue where ALTER TABLE CHANGE COLUMN does not seem
>> to be working.
>>
>> I have a table with a column data type looking like array<struct<a:int,
>> b:int>> and I am trying to it change to array<struct<a:int, b:int,
>> c:string>> based
>> on the underlying data schema change.
>>
>> The alter command succeeds and subsequent describe call shows me the
>> updated table structure. But when tried querying the table,
>> it returns null for the newly added field.
>>
>> This does not happen when a new table with updated column data type is
>> created.
>>
>> Is this a known bug?
>>
>> Thanks,
>> Hardik.
>>
>> PS:- My alter command: ALTER TABLE hardiktest CHANGE COLUMN col1 col2
>> array<struct<a:int, b:int, c:string>>.
>>
>
>
>
> --
> Nitin Pawar
>

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*Dean Wampler, Ph.D.*
thinkbiganalytics.com
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