true, i think. 
but don't rush to OrderPreservingPartitioners. it may be better to create another key CF for sorting the key (put the key in column, which is sorted automatically). to paginate through the records, you get a sorted slice of keys from the key CF, and then look up the record CF with each key.

One issue i found with the default column sorting is that the timeUUIDType sorts time-uuid column in ascending order instead of descending order. get_slice call returns oldest time-uuid instead of most recent time-uuid. Is this a bug?  normally, you want get_slice returns most recent timeuuid, which make function like "get most recent 10 records" easy.

-aj

On Sun, May 9, 2010 at 12:00 AM, David Boxenhorn <david@lookin2.com> wrote:
This is something that I'm not sure that I understand. Can somebody confirm/deny that I understand it? Thanks.

If you use random partitioning, you can loop through all keys with a range query, but they will not be sorted.

True or False?

On Sat, May 8, 2010 at 3:45 AM, AJ Chen <ajchen@web2express.org> wrote:
thanks, that works. -aj


On Fri, May 7, 2010 at 1:17 PM, Stu Hood <stu.hood@rackspace.com> wrote:
Your IPartitioner implementation decides how the row keys are sorted: see http://wiki.apache.org/cassandra/StorageConfiguration#Partitioner . You need to be using one of the OrderPreservingPartitioners if you'd like a reasonable order for the keys.

-----Original Message-----
From: "AJ Chen" <ajchen@web2express.org>
Sent: Friday, May 7, 2010 3:10pm
To: user@cassandra.apache.org
Subject: key is sorted?

I have a super column family for "topic", key being the name of the topic.
<ColumnFamily Name="Topic" CompareWith="UTF8Type" ColumnType="Super"
CompareSubcolumnsWith="BytesType" />
When I retrieve the rows, the rows are not sorted by the key. Is the row key
sorted in cassandra by default?

-aj
--
AJ Chen, PhD
Chair, Semantic Web SIG, sdforum.org
http://web2express.org
twitter @web2express
Palo Alto, CA, USA





--
AJ Chen, PhD
Chair, Semantic Web SIG, sdforum.org
http://web2express.org
twitter @web2express
Palo Alto, CA, USA




--
AJ Chen, PhD
Chair, Semantic Web SIG, sdforum.org
http://web2express.org
twitter @web2express
Palo Alto, CA, USA