Hi Mikael-

Specifically here...

http://hbase.apache.org/book.html#arch.catalog.meta

... and in the rest of Arch where it describes Regions/CF/StoreFile
writing.

Also, take a look at this...

http://hbase.apache.org/book.html#trouble.namenode.hbase.objects


.. For a description of what the file-hierarchy looks like on HDFS.


On 10/28/11 5:33 AM, "Mikael Sitruk" <[email protected]> wrote:

>Hi Doug
>The architecture chapter is not really clear on this feature (unless i
>missed something), nevertheless i can understand from your answer that the
>time of the operation is related to the number of region.
>
>I found for the 0.92 release
>https://issues.apache.org/jira/browse/HBASE-4213 (which is not resolved
>yet)
>https://issues.apache.org/jira/browse/HBASE-1730 (resolved)
>1730 is the generic answer for the above (perhaps 4213 should be also
>marked
>as resolved?)
>Do you know when the 0.92 is planed to be released?
>
>Thanks
>Mikael.S
>
>On Thu, Oct 27, 2011 at 3:34 PM, Doug Meil
><[email protected]>wrote:
>
>> Online table changes is a feature on TRUNK/.92 (dev-list, please
>>comment).
>>  However, for .90 and before you need to disable.  Long story short,
>>this
>> has to do with the fact that the CFs metadata needs to be propagated to
>>all
>> the regions.
>>
>> For background, see:  http://hbase.apache.org/book.html#architecture
>>
>>
>> ________________________________________
>> From: Mikael Sitruk [[email protected]]
>> Sent: Thursday, October 27, 2011 3:19 AM
>> To: [email protected]
>> Subject: Adding a column family restriction
>>
>> Hi
>>
>> I have table in which I need to add column family. Nevertheless while
>> trying
>> todo this via API or from shell this operation cannot be complete
>>without
>> disabling the table first. From the business point of view i cannot
>>affort
>> disabling the table.
>>
>> So my questions are:
>> Why such restriction exist? I can understand for deleting a column
>>family
>> by
>> why for creating a new one?
>> Is there a plan to enable this in the future?
>> I have noticed that disabling/enabling table time is different from
>>table
>> to
>> table, what is the factor affecting the disable/enable time (number of
>> regions/volume of the table...)?
>>
>> I also suggest to update the Javadoc to reflect this restriction on the
>> operation (currently no trace of this restriction in the javadoc)
>>
>> Thanks
>> Regards,
>> Mikael.S
>>
>>
>
>
>-- 
>Mikael Sitruk


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