On Fri, Nov 4, 2011 at 4:59 PM, Vlad Paiu <firstname.lastname@example.org>
I'm a new user of Cassandra and I think it's great.
Still, while developing my APP using Cassandra, I got stuck with some things and I'm not really sure that Cassandra can handle them at the moment.
So, first of all, does Cassandra allow for Counters and regular Keys to be located in the same ColumnFamily ?
What do you mean when you say "regular Keys"? If you are hinting at columns apart from counters, then the answer is *no*: only counters can exist in a CounterColumnFamily and other column families cannot hold counters.
Secondly, is there any way to dynamically set the TTL for a key ? In the sense that I have a key, I initially set it with no TTL, but after a while I decide that it should expire in 100 seconds. Can Cassandra do this ?
TTL is not for one key, it is for one column.
3. Can counters have a TTL ?
No. Currently, counters do not (or if I am correct - cannot) have TTL.
4. Is there any way to atomically reset a counter ? I read on the website that the only way to do it is read the variable value, and then set it to -value, which seems rather bogus to me.
I think that is the only way to reset a counter. I would like to know if there is another way.
Background: I am using Cassandra since the past two months. Hope the community corrects me if I am wrong.
Amit S. Chavan