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From Pavel Kogan <pavel.ko...@cortica.com>
Subject Re: Merging keyspaces
Date Fri, 27 Jun 2014 17:57:45 GMT
Thanks Robert.

When I look at column families files it seems like the format is:

[keyspace]-[cf]-jb-[number]-CompressionInfo.db
[keyspace]-[cf]-jb-[number]-Data.db
[keyspace]-[cf]-jb-[number]-Filter.db
[keyspace]-[cf]-jb-[number]-Index.db
[keyspace]-[cf]-jb-[number]-Statistics.db
[keyspace]-[cf]-jb-[number]-Summary.db
[keyspace]-[cf]-jb-[number]-TOC.txt

So basically when I rename all files during merge of keyspaces, I will
substitute dest keyspace, column family is the same cause it is same
scheme, and I will chose arbitrary number just to avoid collision, correct?
What is the range? I can select any number?

Regards,
  Pavel





On Fri, Jun 27, 2014 at 1:35 PM, Robert Coli <rcoli@eventbrite.com> wrote:

> On Fri, Jun 27, 2014 at 8:28 AM, Pavel Kogan <pavel.kogan@cortica.com>
> wrote:
>
>> I want to merge one keyspace (A) data into another (B) with exactly same
>> scheme. The partition keys of all records are unique in both keyspaces. Can
>> I just copy all files under keyspace A column families into keyspace B
>> column families folders, after running nodetool flush? Is filenames
>> collision possible?
>>
>
> 1) yes, you can do this. the most space efficient way to do so would be
> with hard links. [1]
>
> 2) yes, filename collision is possible, be careful to avoid it.
>
> 3) you should copy/hard-link/move the files with the node down, instead of
> trying to use "nodetool refresh" (which is unsafe)
>
> =Rob
> [1]
> https://issues.apache.org/jira/browse/CASSANDRA-1585?focusedCommentId=13488959&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13488959
>
>
>

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