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HBase, mail # user - Queries regarding Put and Scanner Result


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Re: Queries regarding Put and Scanner Result
Andrey Stepachev 2010-09-23, 05:28
2010/9/23 Imran M Yousuf <[EMAIL PROTECTED]>:
> Hi,
>
>
> Second, when doing object to row, we are mapping a one to many
> relation in a specific column family, e.g. cf1, now when I will update
> the row I will populate cf1 with values set newly, e.g. old values are
> 1,2,3 and new values are 1,3,4, now I will populate cf1 to have 1,3,4.
> Now my first question is what will happen to the value '2'? When I do
> a scan/get on that row will cf1 return 1,3,4 or 1,2,3,4? If the answer
> is 1,2,3,4, when getting cf1 I want to get 1,3,4 only as it was set
> and not 2, what is the best way to achieve it?

How you populate family cf1? 1,2,3,4 = are qualifiers? or you put values
under the same qualifiers?

In case of qualifiers, you should delete qualifier+value explicitly.
This can be done in two ways:
1. delete whole cf for given key
http://hbase.apache.org/docs/r0.20.6/api/org/apache/hadoop/hbase/client/Delete.html#deleteFamily(byte[],
long)

2. get current values, make diff with new value, and delete obsolete value.

>
> Thank you,
>
> --
> Imran M Yousuf
> Twitter: @imyousuf - http://twitter.com/imyousuf
> Blog: http://imyousuf-tech.blogs.smartitengineering.com/
> Mobile: +880-1711402557
>