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From "Hiller, Dean" <Dean.Hil...@nrel.gov>
Subject Re: Option for ordering columns by timestamp in CF
Date Fri, 12 Oct 2012 12:12:12 GMT
Good, I wasn't the only one confused…I was not sure at all how "make column timestamps optional"
was related to your question either…..he must have been a hurry and misread the question.

From: Ertio Lew <ertiop93@gmail.com<mailto:ertiop93@gmail.com>>
Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Date: Friday, October 12, 2012 12:13 AM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Subject: Re: Option for ordering columns by timestamp in CF

"Make column timestamps optional"- kidding me, right ?:)  I do understand that this wont be
possible as then cassandra wont be able to distinguish the latest among several copies of
same column. I dont mean that. I just want the while ordering the columns, Cassandra(in an
optional mode per CF) should not look at column names(they will exist though but for retrieval
purposes not for ordering) but instead Cassandra would order the columns by looking at the
timestamp values(timestamps would exist!). So the change would be just to provide a mode in
which cassandra, while ordering, uses timestamps instead of column names.

On Fri, Oct 12, 2012 at 2:26 AM, Tyler Hobbs <tyler@datastax.com<mailto:tyler@datastax.com>>
wrote:
Without thinking too deeply about it, this is basically equivalent to disabling timestamps
for a column family and using timestamps for column names, though in a very indirect (and
potentially confusing) manner.  So, if you want to open a ticket, I would suggest framing
it as "make column timestamps optional".


On Wed, Oct 10, 2012 at 4:44 AM, Ertio Lew <ertiop93@gmail.com<mailto:ertiop93@gmail.com>>
wrote:
I think Cassandra should provide an configurable option on per column family basis to do columns
sorting by time-stamp rather than column names. This would be really helpful to maintain time-sorted
columns without using up the column name as time-stamps which might otherwise be used to store
most relevant column names useful for retrievals. Very frequently we need to store data sorted
in time order. Therefore I think this may be a very general requirement & not specific
to just my use-case alone.

Does it makes sense to create an issue for this ?




On Fri, Mar 25, 2011 at 2:38 AM, aaron morton <aaron@thelastpickle.com<mailto:aaron@thelastpickle.com>>
wrote:
If you mean order by the column timestamp (as passed by the client) that it not possible.

Can you use your own timestamps as the column name and store them as long values ?

Aaron

On 25 Mar 2011, at 09:30, Narendra Sharma wrote:

> Cassandra 0.7.4
> Column names in my CF are of type byte[] but I want to order columns by timestamp. What
is the best way to achieve this? Does it make sense for Cassandra to support ordering of columns
by timestamp as option for a column family irrespective of the column name type?
>
> Thanks,
> Naren





--
Tyler Hobbs
DataStax<http://datastax.com/>



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