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From Chris Goffinet <goffi...@digg.com>
Subject Re: Why Cassandra is "space inefficient" compared to MySQL?
Date Tue, 25 May 2010 17:37:48 GMT
My money is on the fact that the serializer is just horribly verbose. It's
using a basic set of the java serializer.

-Chris


On Tue, May 25, 2010 at 10:02 AM, Ryan King <ryan@twitter.com> wrote:

> 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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