Thanks for your answer. See my reply in-line.
On 11/04/2011 01:46 PM, Amit Chavan wrote:
Yes, this is what I was asking. Thanks for the answer.
On Fri, Nov 4, 2011 at 4:59 PM, Vlad
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.
When I was saying 'Key' I actually meant to say column. Seems I'm
not yet very acquainted with Cassandra terminology. So in the end,
can you dynamically alter the TTL of a Column ?
Ok. Any info if this will be implemented anytime soon ?
3. Can counters have a TTL ?
No. Currently, counters do not (or if I am correct -
cannot) have TTL.
Ok then, waiting for someone to confirm. It's bad that you cannot
atomically reset a counter value, as a two-way resetting might lead
to undetermined behaviour.
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.
Also, can I set the counter to a specific value, without keeping
state on the client ? For example, if the client does not know the
current counter value is 3. Can it set the counter value to 10,
without first getting the counter value, and then incrementing by 7
I am using Cassandra since the past two months. Hope the
community corrects me if I am wrong.
Amit S. Chavan