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From Ryan King <r...@twitter.com>
Subject Re: Why Cassandra is "space inefficient" compared to MySQL?
Date Tue, 25 May 2010 17:02:19 GMT
Also, timestamps for each column.

-ryan

On Tue, May 25, 2010 at 5:41 AM, Jonathan Ellis <jbellis@gmail.com> wrote:
> That's true.  But fundamentally Cassandra is expected to use more
> space than mysql for a few reasons; usually the biggest factor is that
> Cassandra has to write out each column name in each row, since column
> names are dynamic unlike in mysql where you declare the columns once
> for the whole table.
>
> 2010/5/25 Peter Schüller <scode@spotify.com>:
>>> Could you please tell me why?
>>
>> There might be pending sstable removals on disk, which won't happen
>> until GC or restart. If you just did a bulk insert and checked
>> diskspace immediately afterwards, I think this is a possible
>> explanation.
>>
>> (See "Write path" on http://wiki.apache.org/cassandra/ArchitectureInternals)
>>
>> --
>> / Peter Schuller aka scode
>>
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of Riptano, the source for professional Cassandra support
> http://riptano.com
>

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