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From Jeremy Davis <jerdavis.cassan...@gmail.com>
Subject Re: Performance Characteristics of CASSANDRA-16 (Memory Efficient Compactions)
Date Mon, 07 Jun 2010 16:51:27 GMT
Reads, ok.. What about Compactions? Is the cost of compacting going to be
ever increasing with the number of columns?



On Sat, Jun 5, 2010 at 7:30 AM, Jonathan Ellis <jbellis@gmail.com> wrote:

> #16 is very simple: it allows you to make very large rows.  That is all.
>
> Other things being equal, doing reads from really big rows will be
> slower (since the row index will take longer to read) and this patch
> does not change this.
>
> On Fri, Jun 4, 2010 at 5:47 PM, Jeremy Davis
> <jerdavis.cassandra@gmail.com> wrote:
> >
> > https://issues.apache.org/jira/browse/CASSANDRA-16
> >
> > Can someone (Jonathan?)  help me understand the performance
> characteristics
> > of this patch?
> > Specifically: If I have an open ended CF, and I keep inserting with ever
> > increasing column names (for example current Time), will things generally
> > work out ok performance wise? Or will I pay some ever increasing penalty
> > with the number of entries?
> >
> > My assumption is that you have bucketed things up for me by column name
> > order, and as long as I don't delete/modify/create a column in one of the
> > old buckets, then things will work out ok. Or is this not at all what is
> > going on?
> >
> > Thanks,
> > -JD
> >
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of Riptano, the source for professional Cassandra support
> http://riptano.com
>

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