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From Siddharth Ubale <siddharth.ub...@syncoms.com>
Subject RE: HBase number of columns
Date Tue, 21 Jun 2016 07:09:08 GMT
Thanks Saad!

-----Original Message-----
From: Saad Mufti [mailto:saad.mufti@gmail.com] 
Sent: Thursday, June 16, 2016 10:30 PM
To: user@hbase.apache.org
Subject: Re: HBase number of columns

There is no real column schema in HBase other than defining the column family, each write
to a column writes a cell with the column name plus value, so in theory number of columns
doesn't really matter. What matters is how much data you read and write.

That said there are settings in the column family schema for DATA_BLOCK_ENCODING that affect
how much actual space each column/cell takes, FAST_DIFF is a decent choice to make sure there
is not too much redundancy by writing the same column name over and over again if lots of
rows have the same column name. There are also compression settings of course.

Hope that helps.


On Wed, Jun 15, 2016 at 7:11 AM, Siddharth Ubale < siddharth.ubale@syncoms.com> wrote:

> Hi,
> As per the official documentation of HBase it is mentioned that HBase 
> typical schema should contain 1 to 3 column families per table ( 
> https://hbase.apache.org/book.html#table_schema_rules_of_thumb ) .
> However there is no mention of how many column qualifiers should a row 
> contain for each column family to see good read & write performance.
> Could anybody let us know their input on how many columns per row is 
> desirable in HBase or how many column qualifiers per column family 
> would be desirable.
> Thanks,
> Siddharth Ubale,
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