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HBase, mail # user - Key Design Question for list data  Copy
link to this message Re: Key Design Question for list data Ian
Varley 2012-04-04, 18:15 Great, glad to help Derek! One
clarification, on space usage: on disk, the row key (and column
family) is repeated for every cell. So if you have rows like:
user123:  columnfamily1: col1:val1, col2:val2, col3:val3
user234:  columnfamily1: col1:val1, col2:val2, col3:val3  What
you really get on disk is:   So, it really is roughly the same
order of storage, whether you make it tall or wide. The key
difference is that you get atomicity on a single row, so you get
the benefits (and detriments) of that if you choose that
approach.  Note also that storefile compression *heavily*
mitigates this repeating on disk (in my experience, you end up
getting space usage on par with an RDBMS (or better) if you use
compression). And prefix compression in me