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HBase, mail # user - schema design: rows vs wide columns


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Re: schema design: rows vs wide columns
Viral Bajaria 2013-04-07, 23:51
I think this whole idea of don't go over a certain number of column
families was a 2+ year old story. I remember hearing numbers like 5 or 6
(not 3) come up when talking at Hadoop conferences with engineers who were
at companies that were heavy HBase users. I agree with Andrew's suggestion
that we should remove that text and replace it with benchmarks. Obviously
we need to provide disclaimers that these are benchmarks based on a
specific schema design and so YMMV.

I have run a cluster with some tables having upwards of 5 CFs but the data
was evenly spread across them. I don't think I saw any performance issues
as such or maybe it got masked but 5 CFs was not a problem at all.

Stack puts out an interesting stat i.e. ~15 CFs at FB. Do they run their
own HBase version ? I feel they do and so they might have some enhancements
which are not available to the community or that is no longer the case ?

Thanks,
Viral
On Sun, Apr 7, 2013 at 3:52 PM, Andrew Purtell <[EMAIL PROTECTED]> wrote:

> Is there a pointer to evidence/experiment backed analysis of this question?
> I'm sure there is some basis for this text in the book but I recommend we
> strike it. We could replace it with YCSB or LoadTestTool driven latency
> graphs for different workloads maybe. Although that would also be a big
> simplification of 'schema design' considerations, it would not be so
> starkly lacking background.
>
> On Sunday, April 7, 2013, Ted Yu wrote:
>
> > From http://hbase.apache.org/book.html#number.of.cfs :
> >
> > HBase currently does not do well with anything above two or three column
> > families so keep the number of column families in your schema low.
> >
> > Cheers
> >
> > On Sun, Apr 7, 2013 at 3:04 PM, Stack <[EMAIL PROTECTED] <javascript:;>>
> > wrote:
> >
> > > On Sun, Apr 7, 2013 at 11:58 AM, Ted <[EMAIL PROTECTED]<javascript:;>>
> > wrote:
> > >
> > > > With regard to number of column families, 3 is the recommended
> maximum.
> > > >
> > >
> > > How did you come up w/ the number '3'?  Is it a 'hard' 3? Or does it
> > > depend?  If the latter, on what does it depend?
> > > Thanks,
> > > St.Ack
> > >
> >
>
>
> --
> Best regards,
>
>    - Andy
>
> Problems worthy of attack prove their worth by hitting back. - Piet Hein
> (via Tom White)
>