Re: Questions About Cassandra

[Jonathan Ellis <jb...@gmail.com>]

On Tue, Oct 27, 2009 at 11:02 AM, Ben Coverston <be...@gmail.com> wrote:
> if you wanted to truncate information (in bulk) from
> the database is there an easy way to use the timestamp field to
> accomplish that? I don't see anything in the API that is related to
> that type of functionality. I imagine it must be possible as logging
> seems to be a natural fit for cassandra.

We're adding support for deleting ranges of data (similar to the range
granularity you can get with get_slice), including across multiple
rows, in https://issues.apache.org/jira/browse/CASSANDRA-336, but you
can already delete row-at-a-time by specifying only the CF granularity
to remove.

It would also be possible to add "erase a whole CF" similar to the sql
standard's TRUNCATE TABLE, but like lots of things right now that's
low priority until someone actually needs it. :)

-Jonathan

(CC-ing cassandra-user)

Re: Questions About Cassandra

[Mark Robson <ma...@gmail.com>]

2009/10/27 Jonathan Ellis <jb...@gmail.com>
>
>
> We're adding support for deleting ranges of data (similar to the range
> granularity you can get with get_slice), including across multiple
> rows, in https://issues.apache.org/jira/browse/CASSANDRA-336, but you
> can already delete row-at-a-time by specifying only the CF granularity
> to remove.
>
>

That is excellent news; people wanting to use Cassandra for audit data need
a way to bulk-expire data efficiently.

I assume that when doing a range delete, the range is efficiently
communicated to all the nodes which contain part of it and they delete their
own bits (which would make sense).

Mark