Hi, The only "safe way" to remove data from Cassandra is through tombstones (TTL / Deletes). I am not sure about the problem you are trying to solve here. Maybe could you let us know a bit more about what you are trying to achieve?
If you are trying to expire old data using a stable % of the disk capacity, I would calculate used space by using the user mode of the cassandra-stress tool, using you schema and inserting data. You could then extrapolate to define the right TTL to use, then make sure to use the appropriate compaction strategy and compaction options. More about tombstones and deletes, fwiw: thelastpickle.com/blog/2016/07/27/about-deletes-and-tombstones.html ----------------------- Alain Rodriguez - @arodream - al...@thelastpickle.com France The Last Pickle - Apache Cassandra Consulting http://www.thelastpickle.com 2016-09-16 12:25 GMT+02:00 INDRANIL BASU <indranil...@yahoo.com>: > Hello All, > Whats the best way to do data purging in C* column families based on > size of the table in the disk apart from TTL? > > > *Thanks and regards,* > *-- IB* > > > ------------------------------ > *From:* Samba <saas...@gmail.com> > *To:* user@cassandra.apache.org > *Sent:* Friday, 16 September 2016 2:34 PM > *Subject:* Re: CASSANDRA-5376: CQL IN clause on last key not working when > schema includes set,list or map > > Thanks Tyler, for identifying that this can be fixed now. > > Here is the JIRA ticket : CASSANDRA-12654 : > > If this is just removing the now obsolete check, then I hope this makes to > 3.10 release. > > Regards, > Samba > > On Fri, Sep 16, 2016 at 1:33 AM, Tyler Hobbs <ty...@datastax.com> wrote: > > That ticket was just to improve the error message. From the comments on > the ticket: > > "Unfortunately, handling collections is slightly harder than what > CASSANDRA-5230 <https://issues.apache.org/jira/browse/CASSANDRA-5230> > aimed for, because we can't do a name query. So this will have to wait for > CASSANDRA-4762 <https://issues.apache.org/jira/browse/CASSANDRA-4762>. In > the meantime, we should obviously not throw an assertion error so attaching > a patch to improve validation." > > However, it seems like this would be possible to support in Cassandra > 3.x. We probably just need to remove the check and verify that it actually > works. Can you open a new JIRA ticket for this? > > On Thu, Sep 15, 2016 at 12:49 PM, Samba <saas...@gmail.com> wrote: > > any update on this issue? > > the quoted JIRA issue (CASSANDRA-5376) is resolved as fixed in 1.2.4 but > it is still not possible (even in 3.7) to use IN operator in queries that > fetch collection columns. > > is the fix only to report better error message that this is not possible > or was it fixed then but the issue resurfaced in regression? > > could you please confirm one way or the other? > > Thanks and Regards, > Samba > > > On Tue, Sep 6, 2016 at 6:34 PM, Samba <saas...@gmail.com> wrote: > > Hi, > > "CASSANDRA-5376: CQL IN clause on last key not working when schema > includes set,list or map" > > is marked resolved in 1.2.4 but i still see the issue (not an Assertion > Error, but an query validation message) > > was the issue resolved only to report proper error message or was it fixed > to support retrieving collections when query contains IN clause of > partition/cluster (last) columns? > > If it was fixed properly to support retrieving collections with IN clause, > then is it a bug in 3.7 release that i get the same message? > > Could you please explain, if it not fixed as intended, if there are plans > to support this in future? > > Thanks & Regards, > Samba > > > > > > -- > Tyler Hobbs > DataStax <http://datastax.com/> > > > > >
