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Posted to user@hbase.apache.org by Yves Langisch <yv...@langisch.ch> on 2012/01/26 19:54:31 UTC

Questions about compression

Hi,

I've a few questions concerning compression:

1) What are the steps to change the compression algorithm (e.g. LZO -> Snappy) for an existing table?
2) How can I copy one table to another (same structure, different compression) in order to make some tests beforehand? Is there any simple shell command for this task?
3) Just to get some insight: Are the rows in the memstores already compressed or does it happen during a flash only?

Thanks
Yves

Re: Questions about compression

Posted by Jean-Daniel Cryans <jd...@apache.org>.

On Thu, Jan 26, 2012 at 10:54 AM, Yves Langisch <yv...@langisch.ch> wrote:
> Hi,
>
> I've a few questions concerning compression:
>
> 1) What are the steps to change the compression algorithm (e.g. LZO -> Snappy) for an existing table?

Change the schema, make sure you have the libs.

> 2) How can I copy one table to another (same structure, different compression) in order to make some tests beforehand? Is there any simple shell command for this task?

Look for the job named CopyTable.

> 3) Just to get some insight: Are the rows in the memstores already compressed or does it happen during a flash only?

At flush.

J-D