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From Inder Pall <inder.p...@gmail.com>
Subject Re: How many column families in one table ?
Date Sun, 04 Aug 2013 14:55:26 GMT
Kevin

Would love to hear your thoughts around hbase  not big table.

Thanks

inder
"you are the average of 5 people you spend the most time with"
On Aug 4, 2013 8:15 PM, "Kevin O'dell" <kevin.odell@cloudera.com> wrote:

> Hi Vimal,
>
>   It really depends on your usage pattern but HBase != Bigtable.
> On Aug 4, 2013 2:29 AM, "Vimal Jain" <vkjk89@gmail.com> wrote:
>
> > Hi,
> > I have tested read performance after reducing number of column families
> > from 14 to 3 and yes there is improvement.
> > Meanwhile i was going through the paper published by google on BigTable.
> > It says
> >
> > "It is our intent that the number of distinct column
> > families in a table be small (in the hundreds at most), and
> > that families rarely change during operation."
> >
> > So Is that theoretical value ( 100 CFs )  or its possible but not with
> the
> > current version of Hbase ?
> >
> >
> > On Tue, Jul 2, 2013 at 12:48 AM, Viral Bajaria <viral.bajaria@gmail.com
> > >wrote:
> >
> > > On Mon, Jul 1, 2013 at 10:06 AM, Vimal Jain <vkjk89@gmail.com> wrote:
> > >
> > > > Sorry for the typo .. please ignore previous mail.. Here is the
> > corrected
> > > > one..
> > > > 1)I have around 140 columns for each row , out of 140 , around 100
> > > columns
> > > > hold java primitive data type , remaining 40 columns  contain
> > serialized
> > > > java object as byte array(Inside each object is an ArrayList). Yes ,
> I
> > do
> > > > delete data but the frequency is very less ( 1 out of 5K operations
> ).
> > I
> > > > dont run any compaction.
> > > >
> > >
> > > This answers the type of data in each cell not the size of data. Can
> you
> > > figure out the average size of data that you insert in that size. For
> > > example what is the length of the byte array ? Also for java primitive,
> > is
> > > it 8-byte long ? 4-byte int ?
> > > In addition to that, what is in the row key ? How long is that in
> bytes ?
> > > Same for column family, can you share the names of the column family ?
> > How
> > > about qualifiers ?
> > >
> > > If you have disabled major compactions, you should run it once a few
> days
> > > (if not once a day) to consolidate the # of files that each scan will
> > have
> > > to open.
> > >
> > > 2) I had ran scan keeping in mind the CPU,IO and other system related
> > > > parameters.I found them to be normal with system load being 0.1-0.3.
> > > >
> > >
> > > How many disks do you have in your box ? Have you ever benchmarked the
> > > hardware ?
> > >
> > > Thanks,
> > > Viral
> > >
> >
> >
> >
> > --
> > Thanks and Regards,
> > Vimal Jain
> >
>

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