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HBase >> mail # user >> Query a version of a column efficiently


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Re: Query a version of a column efficiently
You may need to setup your Eclipse workspace and search using
references etc.To get started, this is one class that uses TimeRange
based matching ...
org.apache.hadoop.hbase.regionserver.ScanQueryMatcher
Also - Get is internally implemented as a Scan over a single row.

Hope this gets you started.
--Suraj

On Thu, Jul 26, 2012 at 4:34 PM, Jerry Lam <[EMAIL PROTECTED]> wrote:
> Hi St.Ack:
>
> Can you tell me which source code is responsible for the logic. The source code in the get and scan doesnt provide an indication of how the setTimeRange works.
>
> Best Regards,
>
> Jerry
>
> Sent from my iPad (sorry for spelling mistakes)
>
> On 2012-07-26, at 18:30, Stack <[EMAIL PROTECTED]> wrote:
>
>> On Thu, Jul 26, 2012 at 11:40 PM, Jerry Lam <[EMAIL PROTECTED]> wrote:
>>> Hi St.Ack:
>>>
>>> Let say there are 5 versions for a column A with timestamp = [0, 1, 3, 6,
>>> 10].
>>> I want to execute an efficient query that returns one version of the column
>>> that has a timestamp that is equal to 5 or less. So in this case, it should
>>> return the value of the column A with timestamp = 3.
>>>
>>> Using the setTimeRange(5,  Long.MAX_VALUE) with setMaxVersion = 1, my guess
>>> is that it will return the version 6 not version 3. Correct me if I'm
>>> wrong.
>>>
>>
>> What Tom says, try it.  IIUC, it'll give you your 3.  It won't give
>> you 6 since that is outside of the timerange (try 0 instead of
>> MAX_VALUE; I may have misled w/ MAX_VALUE... it might work but would
>> have to check code).
>>
>> St.Ack