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Posted to user@cassandra.apache.org by Johannes Schaback <jo...@visual-meta.com> on 2009/10/21 18:54:46 UTC

flushing/clearing an entire ColumnFamily

Hi

I am currently using a ColumnFamily as an intermediate store for data
that is computationally expensive and too large to keep in memory. The
data is later composed in a final, long-term ColumnFamily so that I
actually dont need the "raw" data to be around anymore. This is why I
am wondering if there is an easy way to clear an entire ColumnFamily?
I could certainly remove() each row individually, but this may take
some time.

What if I would just delete the content of the data folder of the
ColumnFamily in question? :)


Thanks

Johannes

Re: flushing/clearing an entire ColumnFamily

Posted by Jonathan Ellis <jb...@gmail.com>.
You had the right idea.  Something like "find datadir -name
'*MyCFName*' | xargs rm" would work fine (you'd want to force a flush
first though to clear out whatever's still in the commit log).

-Jonathan

On Wed, Oct 21, 2009 at 11:59 AM, Johannes Schaback
<jo...@visual-meta.com> wrote:
> um, silly me, there's no data folder for each ColumnFamily of course.
> I am still wondering how to delete entire ColumnFamilies...
>
> On Wed, Oct 21, 2009 at 6:54 PM, Johannes Schaback
> <jo...@visual-meta.com> wrote:
>> Hi
>>
>> I am currently using a ColumnFamily as an intermediate store for data
>> that is computationally expensive and too large to keep in memory. The
>> data is later composed in a final, long-term ColumnFamily so that I
>> actually dont need the "raw" data to be around anymore. This is why I
>> am wondering if there is an easy way to clear an entire ColumnFamily?
>> I could certainly remove() each row individually, but this may take
>> some time.
>>
>> What if I would just delete the content of the data folder of the
>> ColumnFamily in question? :)
>>
>>
>> Thanks
>>
>> Johannes
>>
>
>
>
> --
> Johannes Schaback
>
> Geschäftsführer (CTO)
>
> http://www.ladenzeile.de
>
> Visual Meta GmbH
> Friedrichstraße 210
> 10969 Berlin
>
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> Fax: +49 (0)3212 1139 819
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>
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> Handelsregister HRB 115795 B, Amtsgericht Charlottenburg
> USt-IdNr.: DE263760203
>

Re: flushing/clearing an entire ColumnFamily

Posted by Johannes Schaback <jo...@visual-meta.com>.
um, silly me, there's no data folder for each ColumnFamily of course.
I am still wondering how to delete entire ColumnFamilies...

On Wed, Oct 21, 2009 at 6:54 PM, Johannes Schaback
<jo...@visual-meta.com> wrote:
> Hi
>
> I am currently using a ColumnFamily as an intermediate store for data
> that is computationally expensive and too large to keep in memory. The
> data is later composed in a final, long-term ColumnFamily so that I
> actually dont need the "raw" data to be around anymore. This is why I
> am wondering if there is an easy way to clear an entire ColumnFamily?
> I could certainly remove() each row individually, but this may take
> some time.
>
> What if I would just delete the content of the data folder of the
> ColumnFamily in question? :)
>
>
> Thanks
>
> Johannes
>



-- 
Johannes Schaback

Geschäftsführer (CTO)

http://www.ladenzeile.de

Visual Meta GmbH
Friedrichstraße 210
10969 Berlin

Tel.: +49 (0)30 252 939 43
Fax: +49 (0)3212 1139 819
E-Mail: johannes.schaback@visual-meta.com

Geschäftsführer: Robert M. Maier, Johannes Schaback
Handelsregister HRB 115795 B, Amtsgericht Charlottenburg
USt-IdNr.: DE263760203