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From Dylan Hutchison <dhutc...@uw.edu>
Subject Re: how to maintain versioning in D4M schema?
Date Thu, 26 Nov 2015 14:13:00 GMT
Suppose your rowid is of the form

node_timestamp

Doing a prefix scan with Range.prefix("node") will cover all the nodes for
any timestamp.  You could choose to put the timestamp somewhere else if you
need to.


On Thu, Nov 26, 2015 at 3:41 AM, shweta.agrawal <shweta.agrawal@orkash.com>
wrote:

> If I append timestamp on rowid. The id which acts as a node will act as a
> different entity.
> How this will be maintained?
>
> Thanks
> Shweta
>
>
> On Thursday 26 November 2015 04:50 PM, Dylan Hutchison wrote:
>
> Hi Shweta,
>
> You have lots of options.  You could append or prepend a timestamp to the
> rowid or column qualifier.  When prepending to the rowid, you may want to
> reverse the timestamp in order to better shard your data (that is, prevent
> all updates at a particular time from going to a single tablet server), at
> the expense of not being able to do range queries on time periods.  You
> could also disable or relax the VersioningIterator.  It depends on what you
> want to do.
>
> On Thu, Nov 26, 2015 at 1:26 AM, shweta.agrawal <shweta.agrawal@orkash.com
> > wrote:
>
>> Hi,
>>
>> I have my data stored in D4M style. I also want to maintain versions of
>> different value on the basis of time.  As in D4M style  data is only in
>> rowid and colQualifier only.
>>
>> Is there any way to achieve versioning in D4M schema?
>>
>> Thanks
>> Shweta
>>
>>
>
>

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