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From Eric Newton <eric.new...@gmail.com>
Subject Re: Change column family
Date Tue, 26 May 2015 12:59:05 GMT
Short answer: no.

Long answer: maybe.

You can write an iterator which will transform:

row, cf1, cq, vis -> value

into:

row, cf2, cq, vis -> value

And if you can do this while maintaining sort order, you can get your new
ColumnFamily transformed during scans and compactions.

But this bit about maintaining the sort order is more complex than it
sounds.

If you have the following:

row, a, cq, vis -> value
row, aa, cq, vis -> value


And you want to transform cf "a" into cf "b":

row, aa, cq, vis -> value
row, b, cq, vis -> value


Your iterator needs to hold the second column in memory, after transforming
the first column.  Tablet server memory for holding Key/Values is not
infinite.

-Eric

On Tue, May 26, 2015 at 8:44 AM, shweta.agrawal <shweta.agrawal@orkash.com>
wrote:

> Hi,
>
> I want to ask, is it possible in accumulo to change the column family
> without changing the whole data.
>
> Suppose my column family is graph1, now i want to rename this column
> family as graph2.
> Is it possible?
>
> Thanks
> Shweta
>

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