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From Yang <teddyyyy...@gmail.com>
Subject Re: custom reconciling columns?
Date Fri, 01 Jul 2011 08:48:14 GMT
https://issues.apache.org/jira/browse/CASSANDRA-2843

thanks
Yang

On Fri, Jul 1, 2011 at 12:09 AM, Sylvain Lebresne <sylvain@datastax.com>wrote:

> I think it's an interesting solution. And we can probably avoid the two
> getTopLevelColumns flavors with at bit a refactor. Let's open a ticket
> however,
> because this is starting to be off-topic for the user mailing list.
>
> --
> Sylvain
>
> On Fri, Jul 1, 2011 at 12:44 AM, Yang <teddyyyy123@gmail.com> wrote:
> > ok, I kind of found the magic bullet , but you can only use it to shoot
> your
> > enemy close really close range :)
> >
> > for read path, the thrift API already limits the output to a list of
> > columns, so it does not make sense to use maps in the internal
> operations.
> > plus the return CF on the read path is not going to be modified/shared by
> > any other threads, so synchronization is not necessary. so
> > the solution is to modify ColumnFamilyStore so that getTopLevelColumns
> takes
> > a returnCF param, instead of always constructing it inside with
> > ColumnFamily.create().
> > so only read path behavior is changed.
> > in read path, we pass in a FastColumnFamily implementation, which uses an
> > ArrayList internally to store sorted columns, and do binary search to
> insert
> > , and merge to addAll(column).
> > I tried out this, it's about 50% faster on rows with 3000 cols.
> >
> > Jonathan: do you think this is a viable approach? the only disadvantage
> is a
> > slight change to getTopLevelColumns so we have 2 flavors of this method
> > Thanks
> > Yang
> >
> > On Wed, Jun 29, 2011 at 5:51 PM, Jonathan Ellis <jbellis@gmail.com>
> wrote:
> >>
> >> On Tue, Jun 28, 2011 at 10:06 PM, Yang <teddyyyy123@gmail.com> wrote:
> >> > I'm trying to see whether there are some easy magic bullets for a
> >> > drop-in
> >> > replacement for concurrentSkipListMap...
> >>
> >> I'm highly interested if you find one. :)
> >>
> >> --
> >> Jonathan Ellis
> >> Project Chair, Apache Cassandra
> >> co-founder of DataStax, the source for professional Cassandra support
> >> http://www.datastax.com
> >
> >
>

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