incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Keith Wright <kwri...@nanigans.com>
Subject Re: Partition maintenance
Date Tue, 18 Dec 2012 16:32:41 GMT
My understanding was that TTLs only apply to columns and not on a per row basis.  This means
that for each column insert you would need to set that TTL.  Does this mean that the amount
of data space used in such a case would be the TTL * the number of columns?  I was hoping
there was a way to set a row TTL.  See older post:  http://comments.gmane.org/gmane.comp.db.cassandra.user/12701

From: Christopher Keller <cnkeller@gmail.com<mailto:cnkeller@gmail.com>>
Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Date: Tuesday, December 18, 2012 11:16 AM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Subject: Re: Partition maintenance

If I'm understanding you correctly, you can write TTL's on each insert.

18 months would be roughly 540 days which would be 46656000 seconds. I've not tried that number,
but I use smaller TTL's all the time and they work fine. Once they are expired they get tombstones
and are no longer searchable. Space is reclaimed as with any tombstone.

--Chris


On Dec 18, 2012, at 11:08 AM, Stephen.M.Thompson@wellsfargo.com<mailto:Stephen.M.Thompson@wellsfargo.com>
wrote:

Hi folks.  Still working through the details of building out a Cassandra solution and I have
an interesting requirement that I’m not sure how to implement in Cassandra:

In our current Oracle world, we have the data for this system partitioned by month, and each
month the data that are now 18-months old are archived to tape/cold storage and then the partition
for that month is dropped.  Is there a way to do something similar with Cassandra without
destroying our overall performance?

Thanks in advance,
Steve

--
"The downside of being better than everyone else is that people tend to assume you're pretentious."


Mime
View raw message