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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: Performance Characteristics of CASSANDRA-16 (Memory Efficient Compactions)
Date Tue, 08 Jun 2010 02:24:36 GMT
of course.  compaction is always O(N) with the size of the data

On Mon, Jun 7, 2010 at 9:51 AM, Jeremy Davis
<jerdavis.cassandra@gmail.com> wrote:
> 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
>
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com

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